SKC111 GSM/GPRS/GNSS Module Datasheet · GSM/GPRS engine and a highly integrated Bluetooth transceiver. The module’s GSM/GPRS engine can work at frequencies of GSM850MHz, EGSM900MHz,

Skylab M&C Technology Co., Ltd

The Ultra-small GSM/GPRS/GNSS Module Datasheet

Model SKC111

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SKC111 GSM/GPRS/GNSS Module

Datasheet

Document Information

Title SKC111 GSM/GPRS/GNSS Module Datasheet

Document type Datasheet

Document number SL-18030031

Revision and date V1.03 31-Mar -2018

Disclosure restriction Public



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This document applicable to the following products：

Product name Type number Product status

SKC111 SKC111-P4C(0921501) Mass Production

SKC111-P2C(0921503) Mass Production

SKC111-P4C(0921505) Mass Production

SKYLAB reserves all rights to this document and the information contained herein. Products, names, logos and

designs described herein may in whole or in part be subject to intellectual property rights. Reproduction, use,

modification or disclosure to third parties of this document or any part thereof without the express permission of

SKYLAB is strictly prohibited.

The information contained herein is provided “as is” and SKYLAB assumes no liability for the use of the

information. No warranty, either express or implied, is given, including but not limited, with respect to the accuracy,

correctness, reliability and fitness for a particular purpose of the information. This document may be revised by

SKYLAB at any time. For most recent documents, visit www.skylab.com.cn.

Copyright © 2018, Skylab M&C Technology Co., Ltd.

SKYLAB® is a registered trademark of Skylab M&C Technology Co., Ltd in China



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Contents

1 General Description ................................................................................................................................................4

2 Applications ............................................................................................................................................................4

3 Features ..................................................................................................................................................................5

4 Application Block Diagram .....................................................................................................................................6

5 Interfaces ................................................................................................................................................................6

6 Power on and down Scenarios...............................................................................................................................8

7 Module Specifications...........................................................................................................................................10

GSM/GPRS ......................................................................................................................................................10

GNSS ...............................................................................................................................................................11

8 Module Pinout and Pin Description ......................................................................................................................12

Module Pinout ..................................................................................................................................................12

Pin Description .................................................................................................................................................13

9 PCB Footprint and Dimensions ............................................................................................................................16

10 Electrical Characteristics ....................................................................................................................................17

11 Manufacturing Process Recommendations .......................................................................................................19

12 Revision History ..................................................................................................................................................20

13 Contact Information ............................................................................................................................................20



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1 General Description

SKC111 is a multi-purpose module which integrates a high performance GNSS engine and a quad-band

GSM/GPRS engine and a highly integrated Bluetooth transceiver.

The module’s GSM/GPRS engine can work at frequencies of GSM850MHz, EGSM900MHz, DCS1800MHz and

PCS1900MHz., with features GPRS multi-slot class 12 and supports the GPRS coding schemes CS-1, CS-2,

CS-3 and CS-4. GSM part of SKC111 is integrated with internet service protocols, such as TCP/UDP, FTP and

PPP. Extended AT commands have been developed for you to use these Internet service protocols easily.

The module’s GNSS engine supports various location and navigation applications, including autonomous GPS,

GLONASS, GALILEO, BEIDOU, SBAS ranging (WAAS, EGNOS, GAGAN, AND MSAS), QZSS, DGPS(RTCM)

and AGPS. In this way, SKC111 auxiliary serial port and GNSS serial port are connected together, so data can be

transferred between GSM and GNSS parts. This makes it very convenient for sending AT command to control

GNSS, firmware upgrading for GNSS, and EPO data download. It is able to achieve the industry’s highest level of

sensitivity, accuracy and TTFF with the lowest power consumption. The embedded flash memory provides

capacity for storing user-specific configurations and allows for future updates.

The module offers a highly integrated Bluetooth radio and baseband processor. It provides superior sensitivity

and class1 output power and thus the quality of the connection with a wide range of Bluetooth devices.

Figure 1: SKC111 Top View

2 Applications

◆ M2M Applications

◆ IOT (internet of things)

◆ Vehicle/Personal Tracking

◆ Wearable Devices

◆ Security Systems

◆ Wireless POS

◆ Industrial PDA



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◆ Smart Metering

◆ Remote Maintenance&Control

3 Features

◆ Quad-Band GSM850/GSM900/DCS1800/PCS1900.

◆ Fully compliant with Bluetooth V3.0.

◆ Supports GPS/GLONASS/BEIDOU/GALILEO.

◆Supports SBAS (WAAS, EGNOS, GAGAN, AND MSAS).

◆ Dual SIM/USIM controller.

◆ 1 external channel auxiliary 10-bit A/D converter.

◆ Supports 1-bit SDIO interface.

◆ Support interface: I2C, PCM, ADC, UARTF UARTL, GPIO.

◆ Supports security key and chip random ID.

◆ DAI port complies with GSM Rec.11.10.

◆ Supports full-duplex hands-free operation.

◆ Supports Microphone input and speaker output.

◆ RoHS compliance meets environment-friendly requirement.

◆ FCC/CE certified.

◆ 18.7mm(L) x 16.0mm(W) x 2.1mm(H) dimension.



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4 Application Block Diagram

Figure 2: SKC111 Block Diagram

5 Interfaces

UART

The SKC111 module houses four UARTs. UARTs support baud rates from 110bps up to 921,600bps and baud

rate auto detection function. It also provides hardware flow control of the RTS/CTS signals and software flow

control.

UARTs can configure data transfer lengths from 5 to 8 bits, with an optional parity bit and one or two stop bits by

software. They can be served by the DMA controller.

I2C

The SKC111 module supports I2C master and slave mode. There are three types of speed mode in the I2C

controllers: standard mode (100k bit/s), fast mode (400k bit/s) and high-speed mode (3.4M bit/s), supporting 7-

bit/10-bit addressing and can be served by the DMA controller. The I2C package size supports up to 65,535 bytes



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per transfer and 256 transfers per transaction in URAM mode and 8 bytes per transfer in FIFO mode.

SIM

The SIM interface supports the functionality of the GSM Phase 1 specification and also the functionality of the

new GSM Phase 2+ specification for FAST 64 kbps SIM card, which is intended to use with a SIM application

tool-kit.

The SIM interface is powered by an internal regulator in the module. Both 1.8V and 3.0V SIM cards are supported.

Dual SIM card function is supported but dual SIM dual standby is not supported.

SDIO

Supports the SDIO card specification version 2.0. However, the controller can only be configured as the host of

the SD memory card. Data rate up to 48 Mbps in serial mode, the module is targeted at 48MHz operating clock

PCM

Supports the master-mode PCM interface. The clock of PCM interface is 256kHz while the frame sync is 8kHz.

Both long sync and short sync interfaces are supported. The PCM interface can transmit 16-bit stereo or 32-bit

mono 8kHz sampling rate voice signal.

ADC

The auxiliary ADC includes the following functional blocks:

• Analog multiplexer: Selects signal from the input channel3. Real-world messages to be monitored,

e.g. temperature, should be transferred to the voltage domain.

• 10-bit A/D converter: Converts the multiplexed input signal to 10-bit digital data.

•Input voltage rang:0-2.8V

AUDIO

AIN can be used for input of microphone and line. An electret microphone is usually used. AIN are differential

input channels

AOUT is used for output of the receiver. This channel is typically used for building a receiver into a handset.

AOUT channel is a differential channel.

All of these audio channels support voice and ringtone output.

PPS



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A pulse per second (1 PPS) is an electrical signal that very precisely indicates the start of a second.

Depending on the source, properly operating PPS signals have an accuracy ranging 10ns. The PPS signals

are used for precise timekeeping and time measurement.

VRTC

In case of a power failure on pin VBAT, real-time clock and backup RAM are supplied through pin VRTC. This

enables the SKC111 GNSS Receiver to recover from power failure with either a hot start or a warm start

(depending on the duration of VCC outage). If no Backup Battery is connected, the receiver performs a cold start

upon powered up.

Backup Battery Power VRTC draws typically 15 uA current in backup state.

VBAT

Regulated power for the SKC111 is required. The input voltage Vcc should be 3.3V to 4.6V range, peak current is

no less than 1.6A. Suitable decoupling must be provided by external decoupling circuitry (10uF and 1uF). It can

reduce the Noise from power supply and increase power stability

GNSS Antenna

The SKC111 GNSS receiver is designed for supporting the passive antenna connected with pin GNSS_ANT. The

gain of active antenna should be no more than 25dB (18~20dB Typical). The maximum noise figure should be no

more than 1.5dB and output impedance is at 50 Ohm.

GSM Antenna

The SKC111 provides an RF antenna pad for antenna connection. The RF trace in host PCB connected to the

module’s RF antenna pad should be coplanar waveguide line or microstrip line, whose characteristic impedance

should be close to 50Ω.

6 Power on and down Scenarios

Power on

The module can be turned on by driving the pin PWRKEY to a low level voltage. An open collector driver circuit is

suggested to control the PWRKEY. A simple reference circuit is illustrated as below.



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Figure 2: Turn on the module with an Open-collector Driver

The other way to control the PWRKEY is through a button directly. A TVS component is indispensable to be

placed nearby the button for ESD protection. For the best performance, the TVS component must be placed

nearby the button. While pressing the key, electrostatic strike may generate from the finger. A reference circuit

is shown in the following figure.

Figure 3: Turn on the module with a button

Note: Make sure that VBAT is stable before pulling down PWRKEY pin. The time of pulling down

PWRKEY pin is recommended to be 100ms.

Power down

The following procedures can be used to turn off the module:

1. Normal power down procedure: Turn off module using the PWRKEY pin.

2. Under-voltage automatic shutdown: Take effect when under-voltage is detected.



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Note: The normal input voltage range is from 3.3V to 4.6V. If the voltage is <3.3V, the module will

automatically shut down.

7 Module Specifications

GSM/GPRS

GSM/GPRS

Power Supply Supply voltage: 3.3V~4.4V. Typical: 3.8V

Current Consumption Maximum: 1.6A

Firmware Upgrade Via UART port

Antenna Type PCB pad with 50 Ohm impedance.

GSM Class Small MS

Frequency Bands

1. Quad-band: GSM850, EGSM900, DCS1800, PCS1900.

2. The frequency bands can be set by AT command.

3. Auto search frequency band, compliant to GSM Phase 2/2+

Data GPRS

GPRS data downlink transfer: max. 85.6kbps

GPRS data uplink transfer: max. 85.6kbps

Coding scheme: CS-1, CS-2, CS-3 and CS-4

Support the protocols PAP usually used for PPP connections

Support Packet Broadcast Control Channel (PBCCH)

Support Unstructured Supplementary Service Data (USSD)

Internet service protocols TCP/UDP, FTP, PPP, HTTP, NTP, PING

Transmit Power Class 4 (2W) at GSM850 and EGSM900

Class 1 (1W) at DCS1800 and PCS1900

GPRS Sensitivity

GPRS multi-slot class 12 (default)

GPRS multi-slot class 1~12 (configurable)

GPRS mobile station class B

SMS Text and PDU mode



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SMS storage: SIM card

SIM Interface Support SIM card: 1.8V, 3.0V

Support dual SIM card (Not support Dual SIM dual standby)

SIM Toolkit Support SAT class 3, GSM 11.14 Release 99

Phonebook Management Support phonebook types: SM, ME, ON, MC, RC, DC, LD, LA

Audio

Speech codec modes: Half Rate/Full Rate/Enhanced Full Rate /Adaptive

Multi-Rate

Embedded one amplifier of class AB with maximum driving power up to

870mW

Support microphone input.

Support speaker out and hand-free speaker out.

UART Interface

Support UARTF and UART debug and UART Auxiliary.

Used for AT command, GPRS data

Support autobauding from 4800bps to 115200bps

UART Auxiliary used for communication with the GNSS Part

GNSS

GNSS

Power Supply Supply voltage: 2.8V~4.3V. Typical: 3.3V

Firmware Upgrade Via UART port

Antenna Type PCB pad with 50 Ohm impedance.

GNSS GPS/GLONASS/BEIDOU/GALILEO

Power Consumption

Acquisition: 37mA @-130dBm (GPS+GLONASS)

Tracking: 30mA @-130dBm (GPS+GLONASS)

Backup: 7uA @V_BCKP=3.3V

Receiver Type BD B1/GPS L1/GALILEO/QZSS

QZSS, SBAS (WAAS,EGNOS,MSAS,GAGAN)

Sensitivity

Acquisition: -149dBm

Reacquisition: -161dBm

Tracking: -167dBm

TTFF(EASY Enabled) Cold Start: <15s average @-130dBm



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Warm Start: <5s average @-130dBm

Hot Start: 1s @-130dBm

Accuracy of 1PPS Signal Typical accuracy±10ns

Time pulse width 100ms

Horizontal Position Accuracy <2.5 m CEP @-130dBm

Data potocal NMEA0183

Update Rate Up to 10Hz, 1Hz by default

Dynamic Performance

Maximum Altitude: 18,000m

Maximum Velocity: 515m/s

Acceleration: 4G

UART Interface

UART port: GNSS_TX and GNSS_ RX

Support baud rate from 4800bps to 115200bps, 9600bps by

default

8 Module Pinout and Pin Description

Module Pinout



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Figure 3: SKC111 Pin Package

Pin Description

Pin No. Pin name Description Remark

1 MICP Voice input positive Voice input

2 MICN Voice input negative

3 AU_HSP Channel1 voice output

positive Support both voice and ringtone

output. 4 AU_HSN Channel1 voice output

negative

5 PWRKEY Power on/off key.Active pull

down.

Pulled down for a moment to turn on

or turn off the system.

6 ADC Analog to digital converter AGPIO57

7 SD_CMD SD command line GPIO32



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8 SD_CLK SD clock GPIO31

9 SD_DATA SD data line0 GPIO33

10 SIM2_CLK SIM2 clock GPIO42

11 SIM2_DATA SIM2 data GPIO40

12 SIM2_RST SIM2 reset GPIO41

13 SIM2_VDD SIM2 power supply.

14 GND Ground GND

15 GNSS_ANT GNSS antenna input port

16 SIM_GND Ground GND

17 1PPS（GNSS PPS） GNSS PPS output.

18 SIM1_VDD SIM1 power supply.

19 SIM1_CLK SIM1 clock GPIO39

20 SIM1_RST SIM1 reset GPIO38

21 SIM1_DATA SIM1 data GPIO37

22 GNSS_TXD GNSS UART transmit data.

DO

GNSS UART port, connected to the

AUX UART. 23 GNSS_RXD GNSS UART receive data.

DI 24 RXD_AUX Auxiliary UART receive

data. DI AUX UART port, UART2，connected

to the GNSS UART. 25 TXD_AUX Auxiliary UART transmit

data. DO

26 GNSS_VCC GNSS power supply. Output "high" level enable GNSS

LDO, +3.3V

27 GND Ground GND

28 GNSS_VCC_EN GNSS power enabled,DO Output "high" level enable GNSS

LDO 29 U1_DBG_TXD3 Debug UART transmit data.

DO Debug UART port, UART3

30 U1_DBG_RXD3 Debug UART receive data.

DI 31 GND Ground GND

32 BT_ANT Bluetooth antenna port Bluetooth antenna port

33 RXD1 UART1 receive data. DI AT command/Firmware download



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34 TXD1 UART1 transmit data. DO

35 RI/I2C_SCL Ring indication GPIO43

36 DCD/I2C_SDA Data carrier detection GPIO44

37 DTR/SIM_PRESENCE/CMCSK Data terminal ready GPIO30

38 CTS/EINT/KCOL2 UART1 clear to send GPIO14

39 RTS/EINT/KCOL1 UART1 request to send GPIO15

40 GND Ground GND

41 RF_ANT GSM/GPRS antenna port

42 GND Ground GND

43 VDD28_OUT 2.8V VDD output

44 GND Ground GND

45 GND Ground GND

46 RESERVED NC Not connect

47 NETLIGHT Network status indication

output

GPIO2

48 GND Ground GND

49 GND Ground GND

50 VBAT Power supply of

GSM/GPRS part

VBAT=3.3-4.6V, maximum current

1.6A. 51 VBAT

52 VRTC Power supply of GNSS part VRTC=2.0-3.3V

53 LOUDSPKN Channel2 voice output

negative

1. Integrate a Class-AB amplifier. 2.

Support both voice and ringtone

output. 54 LOUDSPKP

Channel2 voice output

positive

55 NC NC

56 NC NC

57 NC NC

58 NC NC

59 PCM_CLK PCM clock RESERVED

60 PCM_OUT PCM data output RESERVED



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61 PCM_SYNC PCM frame synchronization RESERVED

62 PCM_IN PCM data input RESERVED

63 NC NC

64 NC NC

65 NC NC

66 NC NC

67 NC NC

68 NC NC

9 PCB Footprint and Dimensions



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Figure 4: SKC111 Recommend PCB Footprint

10 Electrical Characteristics

a) Absolute Maximum Ratings

Parameter Condition Min Typ. Max. Unit

Storage temperature range -40 125 °C

ESD Protection VESD / 2000 V

Supply voltage VBAT -0.3 4.4 V

Supply voltage GNSS_VCC -0.3 4.4 V

Supply voltage VRTC -0.3 3.3 V

Voltage on any I/O pin -0.3 3.63 V

Voltage on any I/O pin -0.3 3.08 V



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Table8-1: Absolute Maximum Ratings

*SKC111 modules are Electrostatic Sensitive Devices and require special precautions while handling.

ESD precautions

The SKC111 modules contain highly sensitive electronic circuitry and are Electrostatic Sensitive Devices (ESD).

Handling the SKC111 modules without proper ESD protection may destroy or damage them permanently.

The SKC111 modules are electrostatic sensitive devices (ESD) and require special ESD precautions typically

applied to ESD sensitive components. Proper ESD handling and packaging procedures must be applied

throughout the processing, handling, transportation and operation of any application that incorporates the

SKC111 module. Don’t touch the module by hand or solder with non-anti-static soldering iron to avoid damage to

the module.

b) Recommended Operation Ratings

Parameter Symbol Minimum Typical Maximum Unit

Extended temp. range TA -20 85 ºC

Power Supply VBAT 3.4 3.8 4.4 V

Power Supply GNSS_VCC 2.8 3.3 4.3 V

Power Supply VRTC 2.0 3.3 3.3 V

Power Output VDD28_OUT 2.7 2.8 2.9 V

Input Low Voltage VIL -0.3 0.42 V

Input High Voltage VIH 2.38 3.63 V

Table8-2: Operating Conditions



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c) Measurement currents

System state Current (Typ.)@3.3V

Sleep mode (GNSS is powered off) 1.2mA@DRX=5

1.3mA@DRX=9

Transmit (Class 4 (2W) at GSM850 and EGSM900) 1.4A

Transmit (Class 1 (1W) at DCS1800 and PCS1900) 1.0A

Table8-3: Power Consumption in Different States

11 Manufacturing Process Recommendations

Figure 5: SKC111Typical Lead-free Soldering Profile

Note: The final soldering temperature chosen at the factory depends on additional external factors like choice of

soldering paste, size, thickness and properties of the baseboard, etc. Exceeding the maximum soldering

temperature in the recommended soldering profile may permanently damage the module.



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12 Revision History

Revision Description Approved Date

V1.01 Initial Release George He 20161010

V1.02 Update Pin Description George He 20171229

V1.03 Update Pin Description George He 20180331

13 Contact Information

Skylab M&C Technology Co., Ltd.

深圳市天工测控技术有限公司

Address: 6 Floor, No.9 Building, Lijincheng Scientific & Technical park, Gongye East Road,

Longhua District, Shenzhen, Guangdong, China

Phone: 86-755 8340 8210（Sales Support）

Phone: 86-755 8340 8510（Technical Support）

Fax: 86-755-8340 8560

E-Mail: [email protected]

Website: www.skylab.com.cn www.skylabmodule.com

http://www.skylab.com.cn/

http://www.skylabmodule.com/

Documents

SKC111 GSM/GPRS/GNSS Module Datasheet · GSM/GPRS engine and a highly integrated Bluetooth transceiver. The module’s GSM/GPRS engine can work at frequencies of GSM850MHz, EGSM900MHz,