High-Speed, High-Side MOSFET Driver with Charge …ww1.microchip.com/downloads/en/DeviceDoc/20005677A.pdfMIC5021 DS20005677A-page 4 2016 Microchip Technology Inc. Gate Fall Time tF

2016 Microchip Technology Inc. DS20005677A-page 1

MIC5021

Features• 12V to 36V Operation• 550 ns Rise/Fall Time Driving 2000 pF• TTL-Compatible Input with Internal Pull-Down

Resistor• Overcurrent Limit• Gate-to-Source Protection• Internal Charge Pump• 100 kHz Operation Guaranteed Over Full Tem-

perature and Operating Voltage Range• Compatible with Current-Sensing MOSFETs• Current-Source Drive Reduces EMI

Applications• Lamp Control• Heater Control• Motor Control• Solenoid Switching• Switch-Mode Power Supplies• Circuit Breaker

General DescriptionThe MIC5021 high-side MOSFET driver is designed tooperate at frequencies up to 100 kHz (5 kHz PWM for2% to 100% duty cycle) and is an ideal choice for highspeed applications such as motor control, SMPS(switch mode power supplies), and applications usingIGBTs. The MIC5021 can also operate as a circuitbreaker with or without automatic retry.

A rising or falling edge on the input results in a currentsource pulse or sink pulse on the gate output. This out-put current pulse can turn on a 2000 pF MOSFET inapproximately 550 ns. The MIC5021 then supplies alimited current (<2 mA), if necessary, to maintain theoutput state.

An overcurrent comparator with a trip voltage of 50 mVmakes the MIC5021 ideal for use with a current-sens-ing MOSFET. An external low value resistor may beused instead of a sensing MOSFET for more preciseovercurrent control. An optional external capacitorplaced from the CT pin to ground may be used to con-trol the current shutdown duty cycle (dead time) from20% to <1%. A duty cycle from 20% to about 75% ispossible with an optional pull-up resistor from CT toVDD. Additional parts of the MIC502x family include theMIC5020 low-side driver and the MIC5022 half-bridgedriver with a cross-conduction interlock. The MIC5021is available in 8-pin SOIC and plastic DIP packages.

Typical Application CircuitMIC5021

PDIP & SOICHigh-Side Driver with Overcurrent Trip and Retry

V DD

INPUT

C T

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

RS E N S E

N-CHANNELPOWER MOSFET

+12V to +36V

MIC50211

2

3

4

8

7

6

5

10μF

2.7nF

LOAD

RS E N S E =50mVITRIP

* INCREASES TIME BEFORE RETRY

OPTIONAL*

High-Speed, High-Side MOSFET Driver with Charge Pump and Overcurrent Limit

MIC5021

DS20005677A-page 2 2016 Microchip Technology Inc.

Package Types

Functional Block Diagram

MIC5021SOIC

Top View

MIC5021PDIP

Top View

1

2

3

4

8

7

6

5

V BOOST

GATE

SENSE-

SENSE+

VDD

INPUT

CT

GND

1

2

3

4

8

7

6

5

VDD

INPUT

CT

GND

V BOOST

GATE

SENSE-

SENSE+

SENSE-SENSE+

6V INTERNAL REGULATOR

CINT

I1

2I1

50mV

INPUTONE-SHOT GATE

CT

6VOFF

ON

FAULT

NORMAL

I210I2

15V

Q1CHARGE

PUMP

VDD

VBOOST

↓↑

TRANSISTOR: 106


MIC50211.0 ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings †Supply Voltage, VDD................................................................................................................................................. +40VInput Voltage, VIN....................................................................................................................................... –0.5V to +15V Sense Differential Voltage........................................................................................................................................±6.5VSENSE+ or SENSE– to GND .................................................................................................................... –0.5V to +36VTimer Voltage .......................................................................................................................................................... +5.5VVBOOST Capacitor ................................................................................................................................................ 0.01 μF

Operating RatingsSupply Voltage, VDD.................................................................................................................................... +12V to +36V † Notice: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.This is a stress rating only and functional operation of the device at those or any other conditions above those indicatedin the operational sections of this specification is not intended. Exposure to maximum rating conditions for extendedperiods may affect device reliability.

DC CHARACTERISTICS Electrical Characteristics: Unless otherwise indicated, TA = +25°C, GND = 0V, VDD = 12V, CT = OPEN, Gate CL = 1500 pF (IRF540 MOSFET).

Parameters Sym. Min. Typ. Max. Units Conditions

DC Supply Current

— — 1.8 4

mA

VDD = 12V, Input = 0V

— — 2.5 6 VDD = 36V, Input = 0V

— — 1.7 4 VDD = 12V, Input = 5V

— — 2.5 6 VDD = 36V, Input = 5V

Input Threshold — 0.8 1.4 2.0 V —

Input Hysteresis — — 0.1 — V —

Input Pull-Down Current — 10 20 40 μA Input = 5V

Current-Limit Threshold — 30 50 70 mV Note 1

Gate On Voltage— 16 18 21

VVDD = 12V (Note 2)

— 46 50 52 VDD = 36V (Note 2)

Gate On-Time (Fixed) tG(ON) 2 6 10 μs Sense Differential 70 mV (Note 8)

Gate Off-Time (Adjustable) tG(OFF) 10 20 50 μs Sense Differential 70 mV, CT = 0 pF (Note 8)

Gate Turn-On Delay tDLH — 500 1000 ns Note 3

Gate Rise Time tR — 400 500 ns Note 4

Gate Turn-Off Delay tDLH — 800 1500 ns Note 5

Note 1: When using sense MOSFETs, it is recommended that RSENSE < 50Ω. Higher values may affect the sense MOSFET’s current transfer ratio.

2: DC measurement.3: Input switched from 0.8V (TTL low) to 2.0V (TTL high), time for gate transition from 0V to 2V.4: Input switched from 0.8V (TTL low) to 2.0V (TTL high), time for gate transition from 2V to 17V.5: Input switched from 2.0V (TTL high) to 0.8V (TTL low), time for gate transition from 20V (gate on voltage)

to 17V.6: Input switched from 2.0V (TTL high) to 0.8V (TTL low), time for gate transition from 17V to 2V.7: Frequency where gate on voltage reduces to 17V with 50% input duty cycle.8: Gate on time tG(ON) and tG(OFF) are not 100% production tested.

MIC5021


Gate Fall Time tF — 400 500 ns Note 6

Max. Operating Frequency fMAX 100 150 — kHz Note 7

DC CHARACTERISTICS (CONTINUED)Electrical Characteristics: Unless otherwise indicated, TA = +25°C, GND = 0V, VDD = 12V, CT = OPEN, Gate CL = 1500 pF (IRF540 MOSFET).

Parameters Sym. Min. Typ. Max. Units Conditions

Note 1: When using sense MOSFETs, it is recommended that RSENSE < 50Ω. Higher values may affect the sense MOSFET’s current transfer ratio.

2: DC measurement.3: Input switched from 0.8V (TTL low) to 2.0V (TTL high), time for gate transition from 0V to 2V.4: Input switched from 0.8V (TTL low) to 2.0V (TTL high), time for gate transition from 2V to 17V.5: Input switched from 2.0V (TTL high) to 0.8V (TTL low), time for gate transition from 20V (gate on voltage)

to 17V.6: Input switched from 2.0V (TTL high) to 0.8V (TTL low), time for gate transition from 17V to 2V.7: Frequency where gate on voltage reduces to 17V with 50% input duty cycle.8: Gate on time tG(ON) and tG(OFF) are not 100% production tested.


MIC5021

TEMPERATURE SPECIFICATIONS (Note 1)Parameters Sym. Min. Typ. Max. Units Conditions

Junction Thermal ResistancesThermal Resistance, PDIP-8Ld JA –40 — 85 °C Maximum Ambient Tem-

peratureThermal Resistance, SOIC-8Ld JA –40 — 85 °C Maximum Ambient Tem-

peratureNote 1: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable

junction temperature and the thermal resistance from junction to air (i.e., TA, TJ, JA). Exceeding the maximum allowable power dissipation will cause the device operating junction temperature to exceed the maximum rating. Sustained junction temperatures above the maximum rating can impact the device reliability.

MIC5021


2.0 TIMING DIAGRAMS

FIGURE 2-1: Normal operation.

FIGURE 2-2: Fault Operation, CT = Open.

FIGURE 2-3: Fault Condition, CT = Grounded.

INPUT 0V

TTL (H)

SOURCE

50mVSENSE +,–DIFFERENTIAL

GATE

0V

15V (MAX.)

INPUT 0V

TTL (H)

SOURCE


GATE

0V

15V (MAX.)

6μs 20μs

INPUT 0V

TTL (H)

SOURCE


GATE

0V

15V (MAX.)

6μs


MIC50213.0 TYPICAL PERFORMANCE CURVES

FIGURE 3-1: Supply Current vs. Supply Voltage.

FIGURE 3-2: Gate Voltage Change vs. Supply Voltage.

FIGURE 3-3: Gate Turn-On Delay vs. Supply Voltage.

FIGURE 3-4: Gate Turn-On Delay vs. Supply Voltage.

FIGURE 3-5: Gate Turn-On Delay vs. Gate Capacitance.

FIGURE 3-6: Gate Turn-Off Delay vs. Supply Voltage.

Note: The graphs and tables provided following this note are a statistical summary based on a limited number ofsamples and are provided for informational purposes only. The performance characteristics listed hereinare not tested or guaranteed. In some graphs or tables, the data presented may be outside the specifiedoperating range (e.g., outside specified power supply range) and therefore outside the warranted range.

0.0

0.5

1.0

1.5

2.0

2.5

5 10 15 20 25 30 35 40

I SU

PP

LY (m

A)

VSUPPLY (V)

VIN = 0V

VIN = 5V

0

5

10

15

20

25

5 10 15 20 25 30 35 40

V GA

TE (V

)

VSUPPLY (V)

VGATE = VGATE – VS U P P L Y

650

700

750

800

850

900

5 10 15 20 25 30 35 40

t ON

4V (n

s)

VSUPPLY (V)

VGATE = VSUPPLY + 4VCL = 1500pF (IRCZ34)

CBOOST = 0.01μF

INCLUDES PROPAGATION DELAY

750

800

850

900

950

1000

5 10 15 20 25 30 35 40

t ON

10V

(ns)

VSUPPLY (V)

VGATE = VSUPPLY + 10VCL = 1500pF (IRCZ34)

CBOOST= 0.01μF


0.0

0.5

1.0

1.5

2.0

2.5

1x100 1x101 1x102 1x103 1x104 1x105

t ON

(μs)

CGATE (pF)

VGATE = VSUPPLY + 4VVSUPPLY = 12V


750

1000

1250

1500

1750

2000

5 10 15 20 25 30 35 40

t OFF

4V

(ns)

VSUPPLY (V)

VGATE = VSUPPLY + 4VRL = 400


CGATE = 1500pF(IRCZ34)

MIC5021


FIGURE 3-7: Overcurrent Retry Duty Cycle vs. Timing Capacitance.

FIGURE 3-8: Input Current vs. Input Voltage.

FIGURE 3-9: Sense Threshold vs. Temperature.

0

5

10

15

20

25

0.1 1 10 100 1000 10000

RE

TRY

DU

TY C

YC

LE (%

)

CT (pF)

NOTE:tON, tOFF TIMEINDEPENDENTOF VSUPPLY

tON = 5μsVSUPPLY = 12V

0

20

40

60

80

100

0 5 10 15 20 25

I IN(μ

A)

VIN (V)

VSUPPLY = 12V

20

30

40

50

60

80

0 20 40 60 80 100 120

VO

LTA

GE

(mV

)

TEMPERATURE (°C)

70


MIC50214.0 PIN DESCRIPTIONSThe descriptions of the pins are listed in Table 4-1.

TABLE 4-1: PIN FUNCTION TABLE Pin Number Pin Name Description

1 VDD Supply (+12V to 36V). Decouple with ≥ 10 μF capacitor.

2 INPUT TTL-Compatible Input. Logic high turns the external MOSFET on. An internal pull-down returns an open pin logic low.

3 CT

Retry Timing Capacitor. Controls the off time (tG(OFF)) of the overcurrent retry cycle (duty cycle adjustment):Open = Approximately 20% duty cycle.Capacitor-to-Ground = Approximately 20% to <1% duty cycle.Pull-Up Resistor = Approximately 20% to approximately 75% duty cycle.Ground = Maintained shutdown upon overcurrent condition.

4 GND Circuit Ground.

5 SENSE+Current-Sense Comparator (+) Input. Connect to high side of sense resistor or cur-rent sensing MOSFET sense lead. A built-in offset in conjunction with RSENSE sets the load overcurrent trip point.

6 SENSE– Current-Sense Comparator (–) Input. Connect to the low side of the sense resistor (usually the high side of the load).

7 GATE Gate Drive. Drives the gate of an external power MOSFET. Also limits VGS to 15V maximum to prevent gate-to-source damage. Will sink-and-source current.

8 VBOOSTCharge Pump Boost Capacitor. A bootstrap capacitor from VBOOST to the FET source pin supplies charge to quickly enhance the gate output during turn-on.

MIC5021


5.0 FUNCTIONAL DESCRIPTIONRefer to the MIC5021 Functional Block Diagram.

5.1 InputA signal greater than 1.4V (nominal) applied to theMIC5021 INPUT causes gate enhancement on anexternal MOSFET turning the MOSFET on.

An internal pull-down resistor ensures that an openinput remains low, keeping the external MOSFETturned off.

5.2 Gate OutputRapid rise and fall times on the gate output are possiblebecause each input state change triggers a one-shotwhich activates a high-value current sink (10I2) for ashort time. This draws a high current though a currentmirror circuit causing the output transistors to quicklycharge or discharge the external MOSFET’s gate.

A second current sink continuously draws the lowervalue of current used to maintain the gate voltage forthe selected state.

An internal charge pump utilizes an external “boost”capacitor connected between VBOOST and the sourceof the external MOSFET (Refer to the Typical Applica-tion Circuit). The boost capacitor stores charge whenthe MOSFET is off. As the MOSFET turns on, itssource to ground voltage increases and is added to thevoltage across the capacitor, raising the VBOOST pinvoltage. The boost capacitor charge is directed throughthe gate pin to quickly charge the MOSFET’s gate to16V maximum above VDD. The internal charge pumpmaintains the gate voltage.

An internal Zener diode protects the external MOSFETby limiting the gate to source voltage.

5.3 SENSE InputsThe MIC5021’s 50 mV (nominal) trip voltage is createdby internal current sources that force approximately5 μA out of SENSE+ and approximately 15 μA (at trip)out of SENSE–. When SENSE– is 50mV or more belowSENSE+, SENSE– steals base current from an internaldrive transistor shutting off the external MOSFET.

5.4 Overcurrent LimitingCurrent source I1 charges CINT upon power up. Anoptional external capacitor connected to CT is kept dis-charged through a MOSFET Q1.

A fault condition (>50 mV from SENSE+ to SENSE–)causes the overcurrent comparator to enable currentsink 2I1 which overcomes current source I1 to dis-charge CINT in a short time. When CINT is discharged,the input is disabled, which turns off the gate output,and CINT and CT are ready to be charged.

When the gate output turns the MOSFET off, the over-current signal is removed from the sense inputs whichdeactivates current sink 2I1.This allows CINT and theoptional capacitor connected to CT to recharge. ASchmitt trigger delays the retry while the capacitor(s)recharge. Retry delay is increased by connecting acapacitor to CT (optional).

The retry cycle will continue until the fault is removed orthe input is changed to TTL low.

If CT is connected to ground, the circuit will not retryupon a fault condition.


MIC50216.0 APPLICATION INFORMATIONThe MIC5021 MOSFET driver is intended for high-sideswitching applications where overcurrent limiting andhigh speed are required. The MIC5021 can controlMOSFETs that switch voltages up to 36V.

6.1 High-Side Switch Circuit Advantages

High-side switching allows more of the load relatedcomponents and wiring to remain near ground potentialwhen compared to low-side switching. This reduces thechances of short-to-ground accidents or failures.

6.2 Speed AdvantageThe MIC5021 is about two orders of magnitude fasterthan the low cost MIC5014 making it suitable forhigh-frequency high-efficiency circuit operation in PWM(pulse width modulation) designs used for motor con-trol, SMPS (switch-mode power supply) and heatingelement control.

Switched loads (on/off) benefit from the MIC5021’s fastswitching times by allowing use of MOSFETs withsmaller safe operating areas. Larger MOSFETs areoften required when using slower drivers.

6.3 Supply VoltageThe MIC5021’s supply input (VDD) is rated up to 36V.The supply voltage must be equal to or greater than thevoltage applied to the drain of the external N-channelMOSFET.

A 16V minimum supply is recommended to producecontinuous on-state, gate drive voltage for standardMOSFETs (10V nominal gate enhancement).

When the driver is powered from a 12V to 16V supply,a logic-level MOSFET is recommended (5V nominalgate enhancement).

PWM operation may produce satisfactory gateenhancement at lower supply voltages. This occurswhen fast switching repetition makes the boost capac-itor a more significant voltage supply than the internalcharge pump.

6.4 Logic-Level MOSFET PrecautionsLogic-level MOSFETs have lower maximumgate-to-source voltage ratings (typically ±10V) thanstandard MOSFETs (typically ±20V). When an externalMOSFET is turned on, the doubling effect of the boostcapacitor can cause the gate-to-source voltage tomomentarily exceed 10V. Internal zener diodes clampthis voltage to 16V maximum which is too high forlogic-level MOSFETs. To protect logic-level MOS-FETs, connect a zener diode (5V ≤ VZENER < 10V) fromgate to source.

6.5 Overcurrent LimitingA 50 mV comparator is provided for current sensing.The low level trip point minimizes I2R losses when apower resistor is used for current sensing.

The adjustable retry feature can be used to handleloads with high initial currents, such as lamps or heat-ing elements, and can be adjusted from the CT connec-tion.

CT to ground maintains gate drive shutdown followingan overcurrent condition.

CT open, or a capacitor to ground, causes automaticretry. The default duty cycle (CT open) is approximately20%. Refer to the Electrical Characteristics whenselecting a capacitor for reduced duty cycle.

CT through a pull-up resistor to VDD increases the dutycycle. Increasing the duty cycle increases the powerdissipation in the load and MOSFET under a fault con-dition. Circuits may become unstable at a duty cycle ofabout 75% or higher, depending on conditions. Cau-tion: The MIC5021 may be damaged if the voltageapplied to CT exceeds the absolute maximum voltagerating.

6.6 Boost Capacitor SelectionThe boost capacitor value will vary depending on thesupply voltage range.

A 0.01 μF boost capacitor is recommended for bestperformance in the 12V to 20V range. (See Figure 6-1.)Larger capacitors may damage the MIC5021.

FIGURE 6-1: 12V to 20V Configuration.If the full 12V to 36V voltage range is required, theboost capacitor value must be reduced to 2.7 nF(Figure 6-2). The recommended configuration for the20V to 36V range is to place the capacitor is placedbetween VDD and VBOOST as shown in Figure 6-3.

V DD

Input

C T

Gnd

V BOOST

Gate

Sense-

Sense+

TTL Input

+12V to +20V

MIC50211

2

3

4

8

7

6

5

10μF

0.01μF

Load

MIC5021


FIGURE 6-2: 12V to 36V Configuration.

FIGURE 6-3: Preferred 20V to 36V Configuration.Do not use both boost capacitors between VBOOST andthe MOSFET source and VBOOST and VDD at the sametime.

6.7 Current-Sense ResistorsLead length can be significant when using low value(<1Ω) resistors for current sensing. Errors caused bylead length can be avoided by using four-terminal cur-rent-sensing resistors. Four-terminal resistors areavailable from several manufacturers.

6.8 Circuits without Current SensingCurrent sensing may be omitted by connecting theSENSE+ and SENSE– pins to the source of the MOS-FET or to the supply. Connecting the sense pins to thesupply is preferred for inductive loads. Do not connectthe sense pins to ground.

FIGURE 6-4: Connecting Sense to Source.

FIGURE 6-5: Connecting Sense to Supply.

6.9 Inductive Load PrecautionsCircuits controlling inductive loads, such as solenoids(Figure 6-6) and motors, require precautions whencontrolled by the MIC5021. Wire wound resistors,which are sometimes used to simulate other loads, canalso show significant inductive properties.

An inductive load releases stored energy when its cur-rent flow is interrupted (when the MOSFET is switchedoff). The voltage across the inductor reverses and theinductor attempts to force current flow. Since the circuitappears open (the MOSFET appears as a very highresistance) a very large negative voltage occurs acrossthe inductor.

V DD

Input

C T

Gnd

V BOOST

Gate

Sense-

Sense+

TTL Input

+20V to +36V

MIC50211

2

3

4

8

7

6

5

10μF

2.7nF

Load

V DD

Input

C T

Gnd

V BOOST

Gate

Sense-

Sense+

TTL Input

+20V to +36V

MIC50211

2

3

4

8

7

6

5

10μF

Load

0.01μF

V DD

Input

C T

Gnd

V BOOST

Gate

Sense-

Sense+

TTL Input

Load

N-ChannelPower MOSFET

V+

MIC50211

2

3

4

8

7

6

5

10μF

0.01μF

V DD

INPUT

C T

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

LOAD


V+

MIC50211

2

3

4

8

7

6

5

10μF

0.01μF


MIC5021

FIGURE 6-6: Solenoid Driver with Current Sensing.

6.9.1 LIMITING INDUCTIVE SPIKESThe voltage across the inductor can be limited by con-necting a Schottky diode across the load. The diode isforward biased only when the load is switched off. TheSchottky diode clamps negative transients to a fewvolts. This protects the MOSFET from drain-to-sourcebreakdown and prevents the transient from damagingthe charge pump by way of the boost capacitor (seeSense Pin Considerations).

The diode should have a peak forward current ratinggreater than the load current. This is because the cur-rent through the diode is the same as the load currentat the instant the MOSFET is turned off.

6.9.2 SENSE PIN CONSIDERATIONSThe sense pins of the MIC5021 are sensitive to nega-tive voltages. Forcing the sense pins much below–0.5V effectively reverses the supply voltage on por-tions of the driver resulting in unpredictable operationor damage.

Figure 6-7 shows current flowing out of the sense leadsof an MIC5021 during a negative transient (inductivekick). Internal Schottky diodes attempt to limit the neg-ative transient by maintaining a low forward drop.

FIGURE 6-7: Inductive Load Turn-Off.Although the internal Schottky diodes can protect thedriver in low-current resistive applications, they areinadequate for inductive loads or the lead inductance inhigh-current resistive loads. Because of their smallsize, the diodes’ forward voltage drop quickly exceeds0.5V as current increases.

6.9.3 EXTERNAL PROTECTIONResistors placed in series with each SENSE connec-tion limit the current drawn from the internal Schottkydiodes during a negative transient. This minimizes theforward drop across the diodes.

During normal operation, sensing current from thesense pins is unequal (5 μA and 15 μA). The internalSchottky diodes are reverse-biased and have no effect.To avoid skewing the trip voltage, the current limitingresistors must drop equal voltages at the trip point cur-rents (see Figure 6-8). To minimize resistor toleranceerror, use a voltage drop lower than the trip voltage of50 mV. 5 mV is suggested.

FIGURE 6-8: Resistor Voltage Drop.

VDD

INPUT

CT

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

RS E N S E

N-CHANNELPOWER MOSFET(IRF540)

+20V TO +36V

MIC50211

2

3

4

8

7

6

5

10μF

SOLENOID(24V, 47Ω)

0.01μF

SCHOTTKYDIODE(1N5822)

(+24V)

(<0.08Ω)

MOSFETTURN-OFF

0V

NEGATIVESPIKE

~VDD

VDD

INPUT

CT

GATE

MIC50211

2

3

4

8

7

6

5

INDUCTIVELOAD

FORWARD DROP ACROSS DIODESALLOWS LEADS TO GO NEGATIVECURRENT FLOWS FROM GROUND (0V)THROUGH THE DIODES TO THE LOAD DURING NEGATIVE TRANSCIENTS.

V DD

INPUT

C T

GND

V BOOST

GATE

SENSE-

SENSE+


MIC50211

2

3

4

8

7

6

5

RS

LOAD

5μA

15μAVR2

R1

R2VR1 = VR2TO AVOID SKEWINGTHE 50mV TRIP POINT.(5mV SUGGESTED)

R1 3 × R2

VR150mV NOMINAL (@ TRIP)

=~

MIC5021


External Schottky diodes are also recommended (seeD2 and D3 in Figure 6-9). The external diodes clampnegative transients better than the internal diodesbecause their larger size minimizes the forward voltagedrop at higher currents.

FIGURE 6-9: Protection from Inductive Kick.

6.9.4 HIGH-SIDE SENSINGSensing the current on the high side of the MOSFETisolates the sense pins from the inductive spike.

FIGURE 6-10: High-Side Sensing.

6.10 Lamp Driver ApplicationIncandescent lamps have a high inrush current (lowresistance) when turned on. The MIC5021 can performa “soft start” by pulsing the MOSFET (overcurrent con-dition) until the filament is warm and its currentdecreases (resistance increases). The sense resistorvalue is selected so the voltage drop across the senseresistor decreases below the sense threshold (50 mV)as the filament becomes warm. The FET is no longerpulsed and the lamp turns completely on.

A lamp may not fully turn on if the filament does notheat up adequately. Changing the duty cycle, senseresistor, or both to match the filament characteristicscan correct the problem.

Soft start can be demonstrated using a #1157 dual fila-ment automotive lamp. The value of RS shown inFigure 6-11 allows for soft start of the higher-resistancefilament (measures approx. 2.1Ω cold or 21Ω hot).

FIGURE 6-11: Lamp Driver with Current Sensing.

6.11 Remote Overcurrent Limiting Reset

In circuit breaker applications where the MIC5021maintains an off condition after an overcurrent condi-tion is sensed, the CT pin can be used to reset theMIC5021.

FIGURE 6-12: Remote Control Circuit.Switching Q1 on pulls CT low which keeps theMIC5021 gate output off when an overcurrent issensed. Switching Q1 off causes CT to appear open.The MIC5021 retries in about 20 μs and continues toretry until the overcurrent condition is removed.

For demonstration purposes, a 680Ω load resistor and3Ω sense resistor will produce an overcurrent conditionwhen the load’s supply (V+) is approximately 12V orgreater.

V DD

INPUT

C T

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

INDUCTIVELOAD


+12V TO +36V

MIC50211

2

3

4

8

7

6

5

10μF

2.7nF

RS E N S E

1.0k

330Ω

R2

D211DQ03

D311DQ03

D1

R1

VDD

INPUT

C T

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

WIREWOUNDRESISTOR(3Ω)

N-CHANNELPOWER MOSFET(IRFZ44)

+12V TO +20V

RS E N S E(< 0.01Ω)

(+12V)

MIC50211

2

3

4

8

7

6

5

10μF

0.01μF

VDD

INPUT

CT

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

RS E N S E(0.041Ω)

N-CHANNELPOWER MOSFET(IRF540)

V+

MIC50211

2

3

4

8

7

6

5

10μF

0.01μF

INCANDESCENTLAMP (#1157)

(+12V)

"( )" VALUES APPLY TO DEMO CIRCUIT.SEE TEXT.

VDD

INPUT

C T

GND

VBOOST

GATE

SENSE-

SENSE+

TTL INPUT

RS E N S E


+12V TO +20V

MIC50211

2

3

4

8

7

6

5

10μF

0.01μF

LOAD

74HC04(EXAMPLE)

2N3904Q1

10k TO100k

RETRY (H)MAINTAINED (L)


MIC5021The gate-to-source configuration (refer to Figure 6-13)is appropriate for resistive and inductive loads. Thisalso causes the smallest decrease in gate output volt-age.

FIGURE 6-13: Gate-to-Source Pull-Down.The gate-to-ground configuration (refer to Figure 6-14)is appropriate for resistive, inductive, or capacitiveloads. This configuration will decrease the gate outputvoltage slightly more than the circuit shown inFigure 6-13.

FIGURE 6-14: Gate-to-Ground Pull-Down.

VDD

INPUT

CT

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

RS E N S E

+12V TO +36V

MIC5021AJB1

2

3

4

8

7

6

5

10μF

2.7nF

LOAD

2.2M

ADD RESISTOR FOR-40°C TO -55°C OPERATION

V DD

INPUT

CT

GND

V BOOST

GATE

SENSE-

SENSE+

TTL INPUT

RS E N S E

+12V TO +36V

MIC5021AJB1

2

3

4

8

7

6

5

10μF

2.7nF

LOAD2.2MADD RESISTOR FOR-40°C TO -55°C OPERATION

MIC5021


7.0 PACKAGING INFORMATION

7.1 Package Marking Information

8-lead PDIP* Example

XXXXXXXX

YYWW

MIC5021YN 1127

8-lead SOIC* Example

XXXXXXXX

YYWW

MIC5021YM 0812

Legend: XX...X Product code or customer-specific informationY Year code (last digit of calendar year)YY Year code (last 2 digits of calendar year)WW Week code (week of January 1 is week ‘01’)NNN Alphanumeric traceability code Pb-free JEDEC® designator for Matte Tin (Sn)* This package is Pb-free. The Pb-free JEDEC designator ( )

can be found on the outer packaging for this package.

●, ▲, ▼ Pin one index is identified by a dot, delta up, or delta down (trianglemark).

Note: In the event the full Microchip part number cannot be marked on one line, it willbe carried over to the next line, thus limiting the number of available charac-ters for customer-specific information. Package may or may not include thecorporate logo.

Underbar (_) and/or Overbar (‾) symbol may not be to scale.

3e

3e


MIC50218-Lead PDIP Package Outline & Recommended Land Pattern

Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging.

MIC5021


8-Lead SOICN Package Outline & Recommended Land Pattern

Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging.


MIC5021APPENDIX A: REVISION HISTORY

Revision A (December 2016)• Converted Micrel document MIC5021 to Micro-

chip data sheet template DS20005677A.• Minor grammatical text changes throughout.

MIC5021


NOTES:


MIC5021PRODUCT IDENTIFICATION SYSTEMTo order or obtain information, e.g., on pricing or delivery, contact your local Microchip representative or sales office.

Examples:a) MIC5021YM: High-Speed, High-Side

MOSFET Driver with Charge Pump and Over-current Limit,–40°C to +85°C (RoHS Compliant),8LD SOIC

b) MIC5021YN: High-Speed, High-SideMOSFET Driver withCharge Pump and Over-current Limit,–40°C to +85°C (RoHSCompliant),8LD Plastic DIP

PART NO. X XX

PackageTemperatureRange

Device

Device: MIC5021: High-Speed, High-Side MOSFET Driver with Charge Pump and Overcurrent Limit

Temperature Range:

Y = –40C to +85C (RoHS Compliant)

Packages: M = 8-Pin SOICN = 8-Pin Plastic DIP

Note 1: Tape and Reel identifier only appears in the catalog part number description. This identifier is used for ordering purposes and is not printed on the device package. Check with your Microchip Sales Office for package availability with the Tape and Reel option.

MIC5021


NOTES:


Information contained in this publication regarding deviceapplications and the like is provided only for your convenienceand may be superseded by updates. It is your responsibility toensure that your application meets with your specifications.MICROCHIP MAKES NO REPRESENTATIONS ORWARRANTIES OF ANY KIND WHETHER EXPRESS ORIMPLIED, WRITTEN OR ORAL, STATUTORY OROTHERWISE, RELATED TO THE INFORMATION,INCLUDING BUT NOT LIMITED TO ITS CONDITION,QUALITY, PERFORMANCE, MERCHANTABILITY ORFITNESS FOR PURPOSE. Microchip disclaims all liabilityarising from this information and its use. Use of Microchipdevices in life support and/or safety applications is entirely atthe buyer’s risk, and the buyer agrees to defend, indemnify andhold harmless Microchip from any and all damages, claims,suits, or expenses resulting from such use. No licenses areconveyed, implicitly or otherwise, under any Microchipintellectual property rights unless otherwise stated.

TrademarksThe Microchip name and logo, the Microchip logo, AnyRate, AVR, AVR logo, AVR Freaks, BeaconThings, BitCloud, CryptoMemory, CryptoRF, dsPIC, FlashFlex, flexPWR, Heldo, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANCheck, LINK MD, maXStylus, maXTouch, MediaLB, megaAVR, MOST, MOST logo, MPLAB, OptoLyzer, PIC, picoPower, PICSTART, PIC32 logo, Prochip Designer, QTouch, RightTouch, SAM-BA, SpyNIC, SST, SST Logo, SuperFlash, tinyAVR, UNI/O, and XMEGA are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

ClockWorks, The Embedded Control Solutions Company, EtherSynch, Hyper Speed Control, HyperLight Load, IntelliMOS, mTouch, Precision Edge, and Quiet-Wire are registered trademarks of Microchip Technology Incorporated in the U.S.A.

Adjacent Key Suppression, AKS, Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut, BodyCom, chipKIT, chipKIT logo, CodeGuard, CryptoAuthentication, CryptoCompanion, CryptoController, dsPICDEM, dsPICDEM.net, Dynamic Average Matching, DAM, ECAN, EtherGREEN, In-Circuit Serial Programming, ICSP, Inter-Chip Connectivity, JitterBlocker, KleerNet, KleerNet logo, Mindi, MiWi, motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, PureSilicon, QMatrix, RightTouch logo, REAL ICE, Ripple Blocker, SAM-ICE, Serial Quad I/O, SMART-I.S., SQI, SuperSwitcher, SuperSwitcher II, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.

Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries.

GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in other countries.

All other trademarks mentioned herein are property of their respective companies.

© 2016, Microchip Technology Incorporated, All Rights Reserved.

ISBN: 978-1-5224-1200-7

Note the following details of the code protection feature on Microchip devices:• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of ourproducts. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such actsallow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Microchip received ISO/TS-16949:2009 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.


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Documents

High-Speed, High-Side MOSFET Driver with Charge …ww1.microchip.com/downloads/en/DeviceDoc/20005677A.pdfMIC5021 DS20005677A-page 4 2016 Microchip Technology Inc. Gate Fall Time tF