MAXIM MAX187, MAX189 Technical data

查询MAX187ACPA供应商

19-0196; Rev 0; 10/93

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

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

__________________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

________________Functional Diagram

________________________________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

PART TEMP. RANGE PIN-PACKAGE

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

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 ± 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

Ordering Information continued on last page.

* Dice are specified at T ** Contact factory for availability and processing to MIL-STD-883.

= +25°C, DC parameters only.

ERROR

(LSB)

⁄2

_________________Pin Configurations

MAX187/MAX189

SAR

AND

DOUT SCLK

SHDN

DAC

OUTPUT

SHIFT

12-BIT

CONTROL

TIMING

GND

+2.5V BANDGAP REFERENCE

(MAX187 ONLY)

REF

T/H

AIN

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

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

AV = 1.638

10k

MAX187 MAX189

________________________________________________________________

REF-

(4.096V)

REF+

COMPARATOR

BUFFER ENABLE/DISABLE

TOP VIEW

AIN

SHDN

REF

Pin Configurations continued on last page.

MAX187

MAX189

DIP

Maxim Integrated Products

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

SCLK CS

DOUT

6 5

GND

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

ABSOLUTE MAXIMUM RATINGS

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

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

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

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

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

SHDN

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

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

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

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

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.

ELECTRICAL CHARACTERISTICS

MAX187/MAX189

(VDD= +5V ±5%; GND = 0V; unipolar input mode; 75ksps, f reference: V capacitor at REF pin; T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC ACCURACY (Note 1)

Resolution 12 Bits

Relative Accuracy (Note 2) MAX18_B ±1 LSB

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

Gain Error (Note 3)

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

DYNAMIC SPECIFICATIONS

Signal-to-Noise plus Distortion Ratio

Total Harmonic Distortion (up to the 5th harmonic)

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

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

REF

= T

to T

MIN

; unless otherwise noted.)

MAX

MAX18_A ±

MAX18_C ±2

MAX18_A ±1 MAX18_B/C ±3 MAX187 ±3 MAX189A ±1 MAX189B/C ±3

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

SINAD 70 dB

THD -80 dB

DD DD DD DD DD

+ 0.3V) + 0.3V) + 0.3V) + 0.3V) + 0.3V)

Continuous Power Dissipation (T

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

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

CLK

, 75ksps)

p-p

REF

= +70°C)

= 4.096V applied to REF pin, 4.7µF

⁄2

LSB

2 _______________________________________________________________________________________

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

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +5V ±5%; GND = 0V; unipolar input mode; 75ksps, f reference: V capacitor at REF pin; T

CONVERSION RATE

Conversion Time t Track/Hold Acquisition Time t Throughput Rate External clock, 4MHz, 13 clocks 75 ksps Aperture Delay t Aperture Jitter <50 ps

ANALOG INPUT

Input Voltage Range 0 to V Input Capacitance (Note 4) 16 pF INTERNAL REFERENCE (MAX187 only, reference buffer enabled)

REF Output Voltage V

REF Short-Circuit Current 30 mA

REF Tempco

Load Regulation (Note 5) 0mA to 0.6mA output load 1 mV EXTERNAL REFERENCE AT REF (Buffer disabled, V Input Voltage Range 2.50 V Input Current 200 350 µA Input Resistance 12 20 kΩ Shutdown REF Input Current 1.5 10 µA

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

REF

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

= T

to T

MIN

; unless otherwise noted.)

MAX

CONV

ACQ

APR

TA= +25°C 4.076 4.096 4.116

REF

TA= T

MAX187AC/BC ±30 ±50 MAX187AE/BE ±30 ±60 MAX187AM/BM ±30 ±80 MAX187C ±30

MIN

to T

REF

MAX

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

CLK

MAX187_C 4.060 4.132 MAX187_E 4.050 4.140 MAX187_M 4.040 4.150

= 4.096V)

= 4.096V applied to REF pin, 4.7µF

REF

5.5 8.5 µs

1.5 µs

10 ns

REF

ppm/°C

+ 50mV V

MAX187/MAX189

_______________________________________________________________________________________ 3

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

SHDN

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +5V ±5%; GND = 0V; unipolar input mode; 75ksps, f reference: V capacitor at REF pin; T

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

REF

= T

to T

MIN

; unless otherwise noted.)

MAX

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DIGITAL INPUTS (SCLK, CS,

SCLK, CSInput High Voltage V SCLK, CSInput Low Voltage V SCLK, CSInput Hysteresis V SCLK, CSInput Leakage I SCLK, CSInput Capacitance C

SHDN

MAX187/MAX189

Input High Voltage V

SHDN

Input Low Voltage V

SHDN

Input Current I

SHDN

Input Mid Voltage V

SHDN

Voltage, Floating V

SHDN

Maximum Allowed

Leakage, Mid Input

)

INH INL

HYST

VIN= 0V or V

(Note 4) 15 pF

INSH

INSL

SHDN

INS

FLT

= VDDor 0V ±4.0 µA

SHDN

= open 2.75 V

SHDN

= open -100 100 nA

DIGITAL OUTPUT (DOUT)

= 5mA 0.4

Output Voltage Low V

Output Voltage High V Three-State Leakage Current I Three-State Output

Capacitance

SINK

OHISOURCE

OUT

= 5V ±10 µA

= 5V (Note 4) 15 pF

= 16mA 0.3

= 1mA 4 V

POWER REQUIREMENTS

Supply Voltage V

Supply Current

Operating mode

Power-down mode 2 10 µA

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

CLK

MAX187 1.5 2.5 MAX189 1.0 2.0

= 4.096V applied to REF pin, 4.7µF

REF

2.4 V

0.8 V

0.15 V ±1 µA

- 0.5 V

0.5 V

1.5 VDD-1.5 V

4.75 5.25 V

Power-Supply Rejection PSR

VDD= +5V, ±5%; external reference, 4.096V; full-scale input (Note 6)

±0.06 ±0.5 mV

4 _______________________________________________________________________________________

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

TIMING CHARACTERISTICS

(VDD= +5.0V ±5%, TA= T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Track/Hold Acquisition Time t

SCLK Fall to Output Data Valid t

Fall to Output Enable t

Rise to Output Disable t SCLK Clock Frequency f SCLK Pulse Width High t SCLK Pulse Width Low t

SCLK Low to Setup Time

Pulse Width t

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

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

Fall

been calibrated.

time needed for the signal to be acquired.

MIN

to T

, unless otherwise noted.)

MAX

ACQ

LOAD

SCLK

CSO

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

ACQ

= high (Note 7) 1.5 µs

= 100pF

= 100pF 100 ns = 100pF 100 ns

MAX18_ _C/E 20 150 MAX18_ _M 20 200

5 MHz 100 ns 100 ns

50 ns

500 ns

MAX187/MAX189

_______________________________________________________________________________________ 5

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

________________________________________________T ypical Operating Characteristics

POWER-SUPPLY REJECTION vs.

0.16

0.14

0.12

0.10

0.08

0.06

0.04

MAX187/MAX189

POWER-SUPPLY REJECTION (mV)

0.02 0

-60 -20 20 60 100 140

SUPPLY CURRENT vs. TEMPERATURE

2.2

1.8

1.4

1.0

SUPPLY CURRENT (mA)

0.6

0.2

-60 -20 20 60 100 140

TEMPERATURE

TEMPERATURE (°C)

MAX187

MAX189

TEMPERATURE (°C)

vs. TEMPERATURE

4.090

4.089

4.088

4.087

4.086

4.085

4.084

4.083

4.082

INTERNAL REFERENCE VOLTAGE (V)

4.081

4.080

REF

-60 -20 20 60 140 TEMPERATURE (°C)

SHUTDOWN SUPPLY CURRENT vs.

TEMPERATURE

6 5

SHUTDOWN SUPPLY CURRENT (µA)

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



100

6 _______________________________________________________________________________________

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