Maxim MAX1241CMJA, MAX1241CESA, MAX1241CEPA, MAX1241BMJA, MAX1241BESA Datasheet

__________________General Description

The MAX1240/MAX1241 are low-power, 12-bit analog­to-digital converters (ADCs) available in 8-pin pack­ages. 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 ser­ial interface.

Power consumption is only 37mW (VDD= 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 exter­nal 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 com­bined with ease of use and small package size make
these converters ideal for remote-sensor and data­acquisition applications, or for other circuits with
demanding power consumption and space require­ments. 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

1

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 TA= +25°C, DC parameters only.

TOP VIEW

1
2
3
4

8
7
6
5

SCLK
CS
DOUT
GND

REF

SHDN

AIN

V

DD

DIP/SO

MAX1240
MAX1241

Pin Configuration

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

PART

MAX1240ACPA

MAX1240BCPA 0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-

PACKAGE

8 Plastic DIP
8 Plastic DIP

INL

(LSB)

±1/2

±1

MAX1240ACSA 0°C to +70°C 8 SO ±1/2

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

7

AIN

T/H

DOUT

6

1

OUTPUT

SHIFT

REGISTER

CONTROL

LOGIC

INT

CLOCK

12-BIT

SAR

8

2

3

5

REF

4

SHDN

2.5V REFERENCE
(MAX1240 ONLY)

GND

SCLK

CS

MAX1240
MAX1241

V

DD

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

(VDD= +2.7V to +3.6V (MAX1240); VDD= +2.7V to +5.25V (MAX1241); 73ksps, f

S

CLK

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

capacitor at REF pin, MAX1241—external reference; V

REF

= 2.500V applied to REF pin; TA= T

MIN

to T

MAX

; unless otherwise noted.)

V

DD

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

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

DD

+ 0.3V)

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

DD

+ 0.3V)

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

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

DD

+ 0.3V)

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

Continuous Power Dissipation (T

A

= +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

V

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

t

CONV

5.5 7.5 µs

Small-Signal Bandwidth

Signal-to-Noise Plus
Distortion Ratio

SINAD

70

dB

2.25 MHz

Full-Power Bandwidth

Total Harmonic Distortion THD

-80
dB

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

80

Up to the 5th harmonic

dB

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)

(VDD= +2.7V to +3.6V (MAX1240); VDD= +2.7V to +5.25V (MAX1241); 73ksps, f

S

CLK

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

capacitor at REF pin, MAX1241—external reference; V

REF

= 2.500V applied to REF pin; TA= T

MIN

to T

MAX

; unless otherwise noted.)

VIN= 0V or V

DD

µA

TA= +25°C

µA100 150

±0.01 ±1I

IN

SCLK, CS Input Leakage

V0.2

Input Current

CONDITIONS

SHDN = 0V

µA±0.01 10

V

HYST

SCLK, CS Input Hysteresis

SHDN = 0V or V

DD

µA

REF Input Current in Shutdown

kΩ18 25

±4.0

SHDN Input Current

Input Resistance

V0.4V

SL

SHDN Input Low Voltage

V

(Note 5)

V

DD

- 0.4V

SH

SHDN Input High Voltage

pF15C

IN

VREF Output Voltage

SCLK, CS Input Capacitance

SHDN = float

nA

SHDN = float

±100

SHDN Max Allowed Leakage,
Mid Input

VVDD/2V

FLT

SHDN Voltage, Floating

V1.1 V

DD

- 1.1V

SM

SHDN Input Mid Voltage

I

SINK

= 5mA

UNITS

MIN TYP MAX

SYMBOLPARAMETER

V

0.4

V

OL

Output Voltage Low

CS = V

DD

(Note 5)

pF15C

OUT

Three-State Output Capacitance

CS = V

DD

µA

I

SOURCE

= 0.5mA

±0.01 ±10I

L

Three-State Leakage Current

VV

DD

- 0.5V

OH

V

VDD≤ 3.6V

0.8V

IL

µF0.1Capacitive Bypass at REF

SCLK, CS Input Low Voltage

V

2.0

V

IH

SCLK, CS Input High Voltage

Output Voltage High

I

SINK

= 16mA

VDD> 3.6V (MAX1241)

0.8

3.0

2.480 2.500 2.520

VInput Voltage Range

1.00

V

DD

+

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

mA

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)

V

DD

= 3.6V

MAX1240/MAX1241

+2.7V, Low-Power,
12-Bit Serial ADCs in 8-Pin SO

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +3.6V (MAX1240); VDD= +2.7V to +5.25V (MAX1241); 73ksps, f

S

CLK

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

capacitor at REF pin, MAX1241—external reference; V

REF

= 2.500V applied to REF pin; TA= T

MIN

to T

MAX

; unless otherwise noted.)

Note 1: Tested at V

DD

= +2.7V.

Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after the full-scale range and

offset have been calibrated.

Note 3: MAX1240—internal reference, offset nulled; MAX1241—external reference (V

REF

= +2.500V), offset nulled.

Note 4: External load should not change during conversion for specified accuracy.
Note 5: Guaranteed by design. Not subject to production testing.
Note 6: Measured as [V

FS

(2.7V) - VFS(V

DD(MAX

)].

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.

SCLK Pulse Width Low t

CL

200 ns

SCLK Pulse Width High t

CH

200 ns

SCLK Clock Frequency f

SCLK

0 2.1 MHz

CS Rise to Output Disable

t

TR

240 ns

SCLK Low to CS Fall Setup Time

t

CS0

50 ns

DOUT Rise to SCLK Rise (Note 5) t

STR

0 ns

CS Pulse Width

t

CS

240 ns

Figure 2, C

LOAD

= 50pF

CS Fall to Output Enable

t

DV

240 nsFigure 1, C

LOAD

= 50pF

PARAMETERS SYMBOL MIN TYP MAX UNITSCONDITIONS

Acquisition Time t

ACQ

1.5 µs

CS = VDD(Note 6)

TIMING CHARACTERISTICS (Figure 8)

(VDD= +2.7V to +3.6V (MAX1240); VDD= +2.7V to +5.25V (MAX1241); TA= T

MIN

to T

MAX

, unless otherwise noted.)

PARAMETERS SYMBOL MIN TYP MAX UNITSCONDITIONS

2.7 3.6MAX1240

2.7 5.25MAX1241

V

DD

Supply Voltage V

±0.3(Note 5)PSRSupply Rejection mV

20 240

SCLK Fall to Output Data Valid t

DO

20 200

ns

Figure 1,
C

LOAD

= 50pF

MAX124_ _C/E
MAX124_ _M

1.4 2.0

Operating
mode

1.6 2.5

V

DD

= 3.6V

3.5 15

V

DD

= 5.25V

V

DD

= 3.6V

V

DD

= 5.25V

I

DD

1.9 10

Power-down, digital inputs
at 0V or V

DD

1.4 3.5

µA

0.9 1.5

V

DD

= 3.6V

MAX1240C
MAX1241A/B

Supply Current

MAX1240A/B

mA

1.6 3.8

V

DD

= 3.6V

V

DD

= 5.25V

0.9 2.8

MAX1241C

POWER REQUIREMENTS

MAX1240/MAX1241

+2.7V, Low-Power,

12-Bit Serial ADCs in 8-Pin SO

_______________________________________________________________________________________

5

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

2.25 2.75 3.25 3.75 4.25 4.75 5.25

OFFSET ERROR

vs. SUPPLY VOLTAGE

MAX1241-03

SUPPLY VOLTAGE (V)

OFFSET ERROR (LSB)

__________________________________________Typical Operating Characteristics

(VDD= 3.0V, V

REF

= 2.5V, f

SCLK

= 2.1MHz, CL= 20pF, TA = +25°C, unless otherwise noted.)

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

24356

OPERATING SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX1241-D

SUPPLY VOLTAGE (V)

OPERATING SUPPLY CURRENT (mA)

RL = ∞
CODE = 101010100000

MAX1241

MAX1240

0.8

0.9

1.0

1.1

1.2

1.3

-60 -20 20 60 100 140

SUPPLY CURRENT vs. TEMPERATURE

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

MAX1241-A/NEW

MAX1241

MAX1240

R

LOAD

= ∞

CODE = 10101010000

DOUT DOUT

6k

DGND

C

LOAD

= 50pF C

LOAD

= 50pF

6k

DGND

+2.7V

b) High-Z to V

OL

and VOH to V

OL

a) High-Z to VOH and VOL to V

OH

Figure 1. Load Circuits for DOUT Enable Time

DOUT DOUT

6k

DGND

C

LOAD

= 50pF C

LOAD

= 50pF

6k

DGND

+2.7V

b) V

OL

to High-Za) V

OH

to High-Z

Figure 2. Load Circuits for DOUT Disable Time