__________________General Description

The MAX1240/MAX1241 are low-power, 12-bit analog-

to-digital converters (ADCs) available in 8-pin pack-

ages. The MAX1240 operates with a single +2.7V to

+3.6V supply, and the MAX1241 operates with a single

+2.7V to +5.25V supply. Both devices feature a 7.5µs

successive-approximation ADC, a fast track/hold

(1.5µs), an on-chip clock, and a high-speed, 3-wire ser-

ial interface.

Power consumption is only 37mW (V

= 3V) at the

73ksps maximum sampling speed. A 2µA shutdown

mode reduces power at slower throughput rates.

The MAX1240 has an internal 2.5V reference, while the

MAX1241 requires an external reference. The MAX1241

accepts signals from 0V to V

REF

, and the reference

input range includes the positive supply rail. An exter-

nal clock accesses data from the 3-wire interface,

which connects directly to standard microcontroller I/O

ports. The interface is compatible with SPI™, QSPI™,

and MICROWIRE™.

Excellent AC characteristics and very low power com-

bined with ease of use and small package size make

these converters ideal for remote-sensor and data-

acquisition applications, or for other circuits with

demanding power consumption and space require-

ments. The MAX1240/MAX1241 are available in 8-pin

DIP and SO packages.

Applications

Battery-Powered Systems

Portable Data Logging

Isolated Data Acquisition

Process Control

Instrumentation

________________________________Features

♦ Single-Supply Operation:

+2.7V to +3.6V (MAX1240)

+2.7V to +5.25V (MAX1241)

♦ 12-Bit Resolution

♦ Internal 2.5V Reference (MAX1240)

♦ Small Footprint: 8-Pin DIP/SO Packages

♦ Low Power: 3.7µW (73ksps, MAX1240)

3mW (73ksps, MAX1241)

66µW (1ksps, MAX1241)

5µW (power-down mode)

♦ Internal Track/Hold

♦ SPI/QSPI/MICROWIRE 3-Wire Serial Interface

♦ Internal Clock

MAX1240/MAX1241

+2.7V, Low-Power,

12-Bit Serial ADCs in 8-Pin SO

________________________________________________________________

Maxim Integrated Products

19-1155; Rev 2; 11/98

SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.

Ordering Information continued at end of data sheet.

Dice are specified at T

= +25°C, DC parameters only.

TOP VIEW

SCLK

DOUT

GND

REF

SHDN

AIN

DIP/SO

MAX1240

MAX1241

Pin Configuration

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

PART

MAX1240ACPA

MAX1240BCPA 0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-

PACKAGE

8 Plastic DIP

INL

(LSB)

±1

MAX1240ACSA 0°C to +70°C 8 SO ±

MAX1240BC/D 0°C to +70°C Dice* ±1

Ordering Information

EVALUATION KIT

AVAILABLE

MAX1240BCSA 0°C to +70°C 8 SO ±1

Functional Diagram

AIN

T/H

DOUT

OUTPUT

SHIFT

CONTROL

LOGIC

INT

CLOCK

12-BIT

SAR

REF

SHDN

2.5V REFERENCE

(MAX1240 ONLY)

GND

SCLK

MAX1240

MAX1241

MAX1240CCPA 0°C to +70°C 8 Plastic DIP ±1

MAX1240CCSA 0°C to +70°C 8 SO ±1

MAX1240/MAX1241

+2.7V, Low-Power,

12-Bit Serial ADCs in 8-Pin SO

2 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS

= +2.7V to +3.6V (MAX1240); V

= +2.7V to +5.25V (MAX1241); 73ksps, f

CLK

= 2.1MHz (50% duty cycle); MAX1240—4.7µF

capacitor at REF pin, MAX1241—external reference; V

REF

= 2.500V applied to REF pin; T

= T

MIN

to T

MAX

; unless otherwise noted.)

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 +6V

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

+ 0.3V)

DOUT Current..................................................................±25mA

Continuous Power Dissipation (T

= +70°C)

Plastic DIP (derate 9.09mW/°C above +70°C) ...........727mW

SO (derate 5.88mW/°C above +70°C)........................471mW

CERDIP (derate 8.00mW/°C above +70°C)................640mW

Operating Temperature Ranges

MAX1240_C_A/MAX1241_C_A .........................0°C to +70°C

MAX1240_E_ A/MAX1241_E_ A.....................-40°C to +85°C

MAX1240_MJA/MAX1241_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.

71.5MAX124_C

Input Voltage Range 0V

REF

Input Capacitance

Aperture Jitter <50 ps

16 pF

MAX124_A

MAX124_B/C

Aperture Delay t

APR

30 nsFigure 8

Track/Hold Acquisition Time t

ACQ

1.5 µs

Throughput Rate 73 kspsf

SCLK

= 2.1MHz

Conversion Time

PARAMETER SYMBOL

MIN TYP MAX

UNITS

±0.5 ±3.0

Offset Error LSB

Differential Nonlinearity DNL ±1 LSB

±1.0

Gain Temperature Coefficient

±0.5 ±4.0

Gain Error (Note 3) LSB±0.5 ±4.0

Resolution 12 Bits

Relative Accuracy (Note 2) INL

±0.5

LSB

CONV

5.5 7.5 µs

Small-Signal Bandwidth

Signal-to-Noise Plus

Distortion Ratio

SINAD

2.25 MHz

Full-Power Bandwidth

Total Harmonic Distortion THD

-80

1.0

-3dB rolloff

MHz

CONDITIONS

Spurious-Free Dynamic Range

ppm/°C

No missing codes over temperature

MAX124_B/C

±0.25

SFDR

MAX124_A/B

Up to the 5th harmonic

MAX124_A/B

MAX124_A

MAX124_A/B

MAX124_C -88

MAX124_C 88

ANALOG INPUT

CONVERSION RATE

DYNAMIC SPECIFICATIONS (10kHz sine-wave input, 0V to 2.500Vp-p, 73ksps, f

SCLK

= 2.1MHz)

DC ACCURACY (Note 1)

ppm/°C

MAX1240/MAX1241

+2.7V, Low-Power,

12-Bit Serial ADCs in 8-Pin SO

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

= +2.7V to +3.6V (MAX1240); V

= +2.7V to +5.25V (MAX1241); 73ksps, f

CLK

= 2.1MHz (50% duty cycle); MAX1240—4.7µF

capacitor at REF pin, MAX1241—external reference; V

REF

= 2.500V applied to REF pin; T

= T

MIN

to T

MAX

; unless otherwise noted.)

= 0V or V

µA

= +25°C

µA100 150

±0.01 ±1I

SCLK, CS Input Leakage

V0.2

Input Current

CONDITIONS

SHDN = 0V

µA±0.01 10

HYST

SCLK, CS Input Hysteresis

SHDN = 0V or V

µA

REF Input Current in Shutdown

kΩ18 25

±4.0

SHDN Input Current

Input Resistance

V0.4V

SHDN Input Low Voltage

(Note 5)

- 0.4V

SHDN Input High Voltage

pF15C

VREF Output Voltage

SCLK, CS Input Capacitance

SHDN = float

±100

SHDN Max Allowed Leakage,

Mid Input

/2V

FLT

SHDN Voltage, Floating

V1.1 V

- 1.1V

SHDN Input Mid Voltage

SINK

= 5mA

UNITS

MIN TYP MAX

SYMBOLPARAMETER

0.4

Output Voltage Low

CS = V

(Note 5)

pF15C

OUT

Three-State Output Capacitance

CS = V

µA

SOURCE

= 0.5mA

±0.01 ±10I

Three-State Leakage Current

- 0.5V

≤ 3.6V

0.8V

µF0.1Capacitive Bypass at REF

SCLK, CS Input Low Voltage

2.0

SCLK, CS Input High Voltage

Output Voltage High

SINK

= 16mA

> 3.6V (MAX1241)

0.8

3.0

2.480 2.500 2.520

VInput Voltage Range

1.00

50mV

MAX1240AC/BC

ppm/°CREF Temperature Coefficient

±30 ±50

REF Short-Circuit Current 30

MAX1240AE/BE ±30 ±60

MAX1240AM/BM ±30 ±80

0mA to 0.2mA output loadLoad Regulation (Note 4) 0.35

µFCapacitive Bypass at REF 4.7

MAX1240C ±30

DIGITAL OUTPUT: DOUT

DIGITAL INPUTS: SCLK,

CCSS

SSHHDDNN

EXTERNAL REFERENCE (V

REF

= 2.500V)

INTERNAL REFERENCE (MAX1240 only)

Part #	MAX1241CCPA
Description	IC ADC LP 12-BIT SERIAL 8-DIP
Category	IC
Availability	In Stock
Qty	4

MAX1241CCPA

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