ADCs - connecting the real world with the virtual world · ADCs within ASICs. S. 20 Leibniz Konferenz 2014 ADCs within ASICs 100 x 10bit counter ADCs, charge measurement. S. 21 Leibniz

S. 1 Leibniz Konferenz 2014

ADCs - connectingthe real world with the virtual world

Stefan Schubert PE GmbH


Table of content- News about PE GmbH- ADC types and principles- ASIC Design examples with ADCs- Measurement of ADCs in ASICs


founded in 1997 in Herrenberg (Stuttgart)

focus on fabless IC-Design

IC supply chain management

establishment of the IC-Design Center Dresden in 2005 Expanding the service to analog/mixed signal IC-Design

Focus on smart power, smart RFID and sensor applications

Acquisition of PE by the French company “Group Serma” in Juli2013

PE Company History


founded in 1994

legally and financially independent privately owned company

Group Serma is composed of 6 companies Serma Technologies

Serma Ingénierie

IDMOS

Productivity Engineering GmbH

HCM.Systrel

Serma GmbH

Overview of Serma


Products and Services for the Industrial Market

Hi-tech electronics

• analog and mixed signal design

• technology migration

• replacement of obsolete

products

• fully independent supply chain

management

• product maintenance and

obsolescence management

• product migration management

Application Specific Standard

Products for the industrial

market ASSPs

Supply chain management

Fabless IC supplier


ADC types and principles


AFE 1

AFE 2

MU

X

MU

X

Calibration

ADC

Memory

Power Supply and Management

en

viro

nm

en

tal d

ata

of

the

real

wo

rld

Signal Processing

A typical Sensor ASIC

ADC


ADC Types in ASICs

FlashDual SlopeSuccessive ApproximationSingle SlopePipelineSigma Delta Charge Balancingand mixtures

A Flash converter requires 2n-1

comparators for an n-bit

conversion -> impractical for more

than 8bit = 255 comparators



Control Logic

Counter

Reference

IntegratorComparator

Charge Discharge

Fixed time measured time

Inte

grat

or

ou

tpu

tvo

ltag

e

1. charge fixed time with input voltage2. Discharge with reference voltage3. Count time until discharged

ADC Types in ASICs



Source: Analog Devices

ADC Types in ASICs



ADC Types in ASICs

Source: Analog Devices

1. Convert 3Bit (MSB) analog to digital2. Convert result back to analog3. Subtract result from input value4. Convert residue in next stage after amplification (LSB)5. Sum up result from both stages



ADC Types in ASICs

1st order Sigma-Delta Modulator


Physical measured values (examples)Pressure=> Capacity (MEMS)=> current => Voltage, Temperature => Resistor (PT100) => VoltageHumidity => Resistor => Voltage, Capacity => current => VoltageRadiation(Pyro/Thermophile) => VoltageLight (solar cell) => current => VoltageResistor (DMS)=> Voltage…

ADCs measure voltages


ASIC design examples with ADCs


- 2 single ended/differential Sensors

capacitive sensing chip

- 12 bit Sigma-Delta converter

ADCs within ASICs

MEMS


3 x 8bit successive approximation2MS/s

Application in smart metering, digital SMPS and power control

ADCs within ASICs


16 bit Delta-Sigma ADC 0,18µm20MS/sSlow conversion speed but high resolution applications

ADCs within ASICs


14bit 5MS/s pipeline ADCIndustrial control ASIC

ADCs within ASICs


10 bit successive approximationconverter with 8 multiplexed inputseach having it‘s own S&H circuit.Conversion speed is >125kS/s.

ADCs within ASICs


ADCs within ASICs

100 x 10bit counter ADCs, charge measurement


Measurement of ADCs in ASIC


Im Beispiel wurde zum Test des ADCs

ein genauer DAC mit hoher Auflösung

(>16 Bit) und geringen Nichtlinearitäten

(max. 15 ppm) als Referenz verwendet.

Measuring the beast


0

1

2

3

4

5

6

7

0 1 2 3 4 5 6 7

ADC Eingang / LSB

AD

C A

us

ga

ng

/ L

SB

Reale Tranferfunktion

Ideal quantisierte

Transferfunktion

Ideale Transferfunktion

DNL

INL

Some key parametersA

DC

dig

ital

ou

tpu

t

ADC analog input

Issues come up with:- Offset of amplifiers- Gain errors- Cross coupling- Parasitics- noiseand others.


0

1000000

2000000

3000000

4000000

5000000

6000000

0 64 128 192 256

ADC-Ergebnis /LSB

Ab

so

lute

Häu

fig

keit

Reale Verteilung

Ideale Verteilung

Input stimulation with clean sinusoidal voltage – bath tub curve

„Bath tub cleaning“

Ab

s. p

rob

abili

ty

Real distrib.Ideal distrib.

ADC conversion results / LSB


AFE 1

AFE 2

MU

X

MU

X

Calibration

ADC

Memory

Power Supply and Management

en

viro

nm

en

tal d

ata

of

the

real

wo

rld

Signal Processing

Design for Testability

driveable observable


Stefan Schubert • Executive VP IC DesignProductivity Engineering GmbH Sachsenallee 9 • 01723 Kesselsdorf • GermanyPhone: +49 35204 777007 • [email protected] • www.pe-gmbh.com

Documents

ADCs - connecting the real world with the virtual world · ADCs within ASICs. S. 20 Leibniz Konferenz 2014 ADCs within ASICs 100 x 10bit counter ADCs, charge measurement. S. 21 Leibniz