Maxim MAX189CEPA, MAX189CCWE, MAX189CCPA, MAX189BMJA, MAX189BCWE Datasheet

...

__________________General Description

The MAX187/MAX189 serial 12-bit analog-to-digital converters (ADCs) operate from a single +5V supply and accept a 0V to 5V analog input. Both parts feature an 8.5µs successive-approximation ADC, a fast track/hold (1.5µs), an on-chip clock, and a high-speed 3-wire serial interface.

The MAX187/MAX189 digitize signals at a 75ksps throughput rate. An external clock accesses data from the interface, which communicates without external hardware to most digital signal processors and microcontrollers. The interface is compatible with SPI™, QSPI™, and Microwire™.

The MAX187 has an on-chip buffered reference, and the MAX189 requires an external reference. Both the MAX187 and MAX189 save space with 8-pin DIP and 16-pin SO packages. Power consumption is 7.5mW and reduces to only 10µW in shutdown.

Excellent AC characteristics and very low power consumption combined with ease of use and small package size make these converters ideal for remote DSP and sensor applications, or for circuits where power consumption and space are crucial.

___________________________Applications

Portable Data Logging Remote Digital Signal Processing Isolated Data Acquisition High-Accuracy Process Control

________________________________Features

♦ 12-Bit Resolution ♦ ±

⁄2 LSB Integral Nonlinearity (MAX187A/MAX189A)

♦ Internal Track/Hold, 75kHz Sampling Rate ♦ Single +5V Operation ♦ Low Power: 2µA Shutdown Current

1.5mA Operating Current

♦ Internal 4.096V Buffered Reference (MAX187) ♦ 3-Wire Serial Interface, Compatible with SPI,

QSPI, and Microwire

♦ Small-Footprint 8-Pin DIP and 16-Pin SO

_________________Ordering Information

MAX187/MAX189

+5V, Low-Power, 12-Bit Serial ADCs

________________________________________________________________

Maxim Integrated Products

Call toll free 1-800-998-8800 for free samples or literature.

19-0196; Rev 0; 10/93

PART TEMP. RANGE PIN-PACKAGE

ERROR

(LSB)

MAX187ACPA 0°C to +70°C 8 Plastic DIP ±

⁄2

MAX187BCPA 0°C to +70°C 8 Plastic DIP ±1 MAX187CCPA 0°C to +70°C 8 Plastic DIP ±2 MAX187ACWE 0°C to +70°C 16 Wide SO ±

⁄2

MAX187BCWE 0°C to +70°C 16 Wide SO ±1 MAX187CCWE 0°C to +70°C 16 Wide SO ±2 MAX187BC/D 0°C to +70°C Dice* ±1

™ SPI and QSPI are trademarks of Motorola. Microwire is a trademark of National Semiconductor.

Ordering Information continued on last page.

* Dice are specified at T

= +25°C, DC parameters only.

** Contact factory for availability and processing to MIL-STD-883.

________________Functional Diagram

GND

REF

AIN

T/H

BANDGAP REFERENCE

+2.5V

(MAX187 ONLY)

10k

AV = 1.638

(4.096V)

REF-

REF+

DAC

OUTPUT

SHIFT

DOUT

SCLK

SHDN

CONTROL

AND

TIMING

12-BIT

SAR

COMPARATOR

BUFFER ENABLE/DISABLE

NOTE: PIN NUMBERS SHOWN ARE FOR 8-PIN DIPs ONLY.

MAX187 MAX189

TOP VIEW

1 2 3 4

8 7 6 5

SCLK CS DOUT GND

REF

SHDN

AIN

DIP

MAX187 MAX189

Pin Configurations continued on last page.

_________________Pin Configurations

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

MAX187/MAX189

+5V, Low-Power, 12-Bit Serial ADCs

2 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS

(VDD= +5V ±5%; GND = 0V; unipolar input mode; 75ksps, f

CLK

= 4.0MHz, external clock (50% duty cycle); MAX187—internal

reference: V

REF

= 4.096V, 4.7µF capacitor at REF pin, or MAX189—external reference: V

REF

= 4.096V applied to REF pin, 4.7µF

capacitor at REF pin; T

= T

MIN

to T

MAX

; unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC ACCURACY (Note 1)

Resolution 12 Bits

MAX18_A ±

⁄2

Relative Accuracy (Note 2) MAX18_B ±1 LSB

MAX18_C ±2

Differential Nonlinearity DNL No missing codes over temperature ±1 LSB Offset Error

MAX18_A ±1

⁄2

LSB

MAX18_B/C ±3

Gain Error (Note 3)

MAX187 ±3

LSB

MAX189A ±1 MAX189B/C ±3

Gain Temperature Coefficient External reference, 4.096V ±0.8 ppm/°C

DYNAMIC SPECIFICATIONS

(10kHz sine wave input, 0V to 4.096V

p-p

, 75ksps)

Signal-to-Noise plus Distortion Ratio

SINAD 70 dB

Total Harmonic Distortion (up to the 5th harmonic)

THD -80 dB

Spurious-Free Dynamic Range SFDR 80 dB Small-Signal Bandwidth Rolloff -3dB 4.5 MHz Full-Power Bandwidth 0.8 MHz

to GND.............................................................-0.3V to +6V

AIN to GND................................................-0.3V to (V

+ 0.3V)

REF to GND...............................................-0.3V to (V

+ 0.3V)

Digital Inputs to GND.................................-0.3V to (V

+ 0.3V)

Digital Outputs to GND..............................-0.3V to (V

+ 0.3V)

SHDN

to GND.............................................-0.3V to (V

+ 0.3V)

REF Load Current (MAX187) .........................4.0mA Continuous

REF Short-Circuit Duration (MAX187)................................20sec

DOUT Current..................................................................±20mA

Continuous Power Dissipation (T

= +70°C) 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)..500mW 16-Pin Wide SO (derate 8.70mW/°C above +70°C)...478mW

8-Pin CERDIP (derate 8.00mW/°C above +70°C) ......440mW

Operating Temperature Ranges:

MAX187_C_ _/MAX189_C_ _.............................0°C to +70°C

MAX187_E_ _/MAX189_E_ _..........................-40°C to +85°C

MAX187_MJA/MAX189_MJA .......................-55°C to +125°C

Storage Temperature Range............................-60°C to +150°C

Lead Temperature (soldering, 10sec)............................+300°C

ABSOLUTE MAXIMUM RATINGS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CONVERSION RATE

Conversion Time t

CONV

5.5 8.5 µs

Track/Hold Acquisition Time t

ACQ

1.5 µs Throughput Rate External clock, 4MHz, 13 clocks 75 ksps Aperture Delay t

APR

10 ns

Aperture Jitter <50 ps

ANALOG INPUT

Input Voltage Range 0 to V

REF

V Input Capacitance (Note 4) 16 pF INTERNAL REFERENCE (MAX187 only, reference buffer enabled)

REF Output Voltage V

REF

TA= +25°C 4.076 4.096 4.116

MAX187_C 4.060 4.132

TA= T

MIN

to T

MAX

MAX187_E 4.050 4.140

MAX187_M 4.040 4.150

REF Short-Circuit Current 30 mA

MAX187AC/BC ±30 ±50

REF Tempco

MAX187AE/BE ±30 ±60

ppm/°C

MAX187AM/BM ±30 ±80

MAX187C ±30 Load Regulation (Note 5) 0mA to 0.6mA output load 1 mV EXTERNAL REFERENCE AT REF (Buffer disabled, V

REF

= 4.096V)

Input Voltage Range 2.50 V

+ 50mV V Input Current 200 350 µA Input Resistance 12 20 kΩ Shutdown REF Input Current 1.5 10 µA

MAX187/MAX189

+5V, Low-Power, 12-Bit Serial ADCs

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +5V ±5%; GND = 0V; unipolar input mode; 75ksps, f

CLK

= 4.0MHz, external clock (50% duty cycle); MAX187—internal

reference: V

REF

= 4.096V, 4.7µF capacitor at REF pin, or MAX189—external reference: V

REF

= 4.096V applied to REF pin, 4.7µF

capacitor at REF pin; T

= T

MIN

to T

MAX

; unless otherwise noted.)

MAX187/MAX189

+5V, Low-Power, 12-Bit Serial ADCs

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +5V ±5%; GND = 0V; unipolar input mode; 75ksps, f

CLK

= 4.0MHz, external clock (50% duty cycle); MAX187—internal

reference: V

REF

= 4.096V, 4.7µF capacitor at REF pin, or MAX189—external reference: V

REF

= 4.096V applied to REF pin, 4.7µF

capacitor at REF pin; T

= T

MIN

to T

MAX

; unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DIGITAL INPUTS (SCLK, CS,

SHDN

)

SCLK, CSInput High Voltage V

INH

2.4 V

SCLK, CSInput Low Voltage V

INL

0.8 V

SCLK, CSInput Hysteresis V

HYST

0.15 V

SCLK, CSInput Leakage I

VIN= 0V or V

±1 µA

SCLK, CSInput Capacitance C

(Note 4) 15 pF

SHDN

Input High Voltage V

INSH

- 0.5 V

SHDN

Input Low Voltage V

INSL

0.5 V

SHDN

Input Current I

INS

SHDN

= VDDor 0V ±4.0 µA

SHDN

Input Mid Voltage V

1.5 VDD-1.5 V

SHDN

Voltage, Floating V

FLT

SHDN

= open 2.75 V

SHDN

Maximum Allowed

SHDN

= open -100 100 nA

Leakage, Mid Input

DIGITAL OUTPUT (DOUT)

Output Voltage Low V

SINK

= 5mA 0.4

SINK

= 16mA 0.3

Output Voltage High V

OHISOURCE

= 1mA 4 V

Three-State Leakage Current I

= 5V ±10 µA

Three-State Output

OUT

= 5V (Note 4) 15 pF

Capacitance

POWER REQUIREMENTS

Supply Voltage V

4.75 5.25 V

Supply Current

Operating mode

MAX187 1.5 2.5

MAX189 1.0 2.0

Power-down mode 2 10 µA

VDD= +5V, ±5%; external reference, 4.096V;

Power-Supply Rejection PSR

full-scale input (Note 6)

±0.06 ±0.5 mV

MAX187/MAX189

+5V, Low-Power, 12-Bit Serial ADCs

_______________________________________________________________________________________ 5

TIMING CHARACTERISTICS

(VDD= +5.0V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Track/Hold Acquisition Time t

ACQ

= high (Note 7) 1.5 µs

SCLK Fall to Output Data Valid t

LOAD

= 100pF

MAX18_ _C/E 20 150

MAX18_ _M 20 200

Fall to Output Enable t

LOAD

= 100pF 100 ns

Rise to Output Disable t

LOAD

= 100pF 100 ns

SCLK Clock Frequency f

SCLK

5 MHz

SCLK Pulse Width High t

100 ns

SCLK Pulse Width Low t

100 ns

SCLK Low to

Fall

CSO

50 ns

Setup Time

Pulse Width t

500 ns

Note 1: Tested at VDD= +5V. Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after the full-scale range has

been calibrated.

Note 3: MAX187—internal reference, offset nulled; MAX189–external +4.096V reference, offset nulled. Excludes reference errors. Note 4: Guaranteed by design. Not subject to production testing. Note 5: External load should not change during conversion for specified ADC accuracy. Note 6: DC test, measured at 4.75V and 5.25V only. Note 7: To guarantee acquisition time, t

ACQ

is the maximum time the device takes to acquire the signal, and is also the minimum

time needed for the signal to be acquired.

MAX187/MAX189

+5V, Low-Power, 12-Bit Serial ADCs

6 _______________________________________________________________________________________

0.12

0.10

0.08

0.06

0.04

0.02 0

-60 -20 20 60 100 140 TEMPERATURE (°C)

POWER-SUPPLY REJECTION (mV)

POWER-SUPPLY REJECTION vs.

TEMPERATURE

0.14

0.16

4.090

4.087

4.084

4.081

-60 -20 20 60 140 TEMPERATURE (°C)

INTERNAL REFERENCE VOLTAGE (V)



REF

vs. TEMPERATURE

100

4.089

4.088

4.086

4.085

4.083

4.082

4.080

1.8

1.4

1.0

0.6

0.2

-60 -20 20 60 100 140 TEMPERATURE (°C)

SUPPLY CURRENT (mA)

MAX187

MAX189

SUPPLY CURRENT vs. TEMPERATURE

2.2

________________________________________________T ypical Operating Characteristics

-60 -20 20 60 100 140 TEMPERATURE (°C)

SHUTDOWN SUPPLY CURRENT (µA)

SHUTDOWN SUPPLY CURRENT vs.

TEMPERATURE

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