Rainbow Electronics MAX1089 User Manual

General Description

The MAX1086–MAX1089 are low-cost, micropower, ser­ial output 10-bit analog-to-digital converters (ADCs)
available in a tiny 8-pin SOT23. The MAX1086/MAX1088
operate with a single +5V supply. The MAX1087/MAX1089
operate with a single +3V supply. The devices feature a
successive-approximation ADC, automatic shutdown,
fast wake-up (1.4µs), and a high-speed 3-wire inter­face. Power consumption is only 0.5mW (VDD= +2.7V)
at the maximum sampling rate of 150ksps.
Autoshutdown™ (0.1µA) between conversions results in
reduced power consumption at slower throughput
rates.

The MAX1086/MAX1087 provide 2-channel, single­ended operation and accept input signals from 0 to
V

REF

. The MAX1088/MAX1089 accept true-differential

inputs ranging from 0 to V

REF

. Data is accessed using
an external clock through the 3-wire SPI™, QSPI™, and
MICROWIRE™–compatible serial interface. Excellent
dynamic performance, low-power, ease of use, and
small package size, make these converters ideal for
portable battery-powered data acquisition applications,
and for other applications that demand low power con­sumption and minimal space.

Applications

Low Power Data Acquisition

Portable Temperature Monitors

Flowmeters

Touch Screens

Features

♦ Single-Supply Operation

+3V(MAX1087/MAX1089)
+5V(MAX1086/MAX1088)

♦ AutoShutdown Between Conversions

♦ Low Power

200µA at 150ksps
130µA at 100ksps
65µA at 50ksps
13µA at 10ksps

1.5µA at 1ksps

0.2µA in Shutdown

♦ True-Differential Track/Hold, 150kHz Sampling Rate

♦ Software-Configurable Unipolar/Bipolar

Conversion (MAX1088/MAX1089 only)

♦ SPI, QSPI, MICROWIRE–Compatible Interface for

DSPs and Processors

♦ Internal Conversion Clock

♦ 8-Pin SOT23 Package

MAX1086–MAX1089

150ksps, 10-Bit, 2-Channel Single-Ended, and

1-Channel True-Differential ADCs in SOT23

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

19-2036; Rev 0; 5/01

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

AutoShutdown is a trademark of Maxim Integrated Products.
SPI and QSPI are trademarks of Motorola Inc.
MICROWIRE is a trademark of National Semiconductor Corp.

PART

MAX1086EKA-T -40°C to +85°C 8 SOT23 AAEZ

MAX1087EKA-T -40°C to +85°C 8 SOT23 AAEV

MAX1088EKA-T -40°C to +85°C 8 SOT23 AAFB

MAX1089EKA-T -40°C to +85°C 8 SOT23 AAEX

TEMP.

RANGE

PIN-

PACKAGE

TOP

MARK

TOP VIEW

1

V

DD

2

MAX1086
MAX1087

AIN2 (AIN-)

( ) ARE FOR THE MAX1088/MAX1089

3

4

MAX1088
MAX1089

SOT23-8

87SCLK

DOUTAIN1 (AIN+)

CNVST

6

REFGND

5

MAX1086–MAX1089

150ksps, 10-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= +2.7V to +3.6V, V

REF

= +2.5V for MAX1087/MAX1089, or VDD = +4.75V to +5.25V, V

REF

= +4.096V for MAX1086/MAX1088,

0.1µF capacitor at REF, f

SCLK

= 8MHz (50% duty cycle), AIN- = GND for MAX1088/MAX1089. TA= T

MIN

to T

MAX,

unless otherwise

noted. Typical values at T

A

= +25°C.)

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.

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

CNVST, SCLK, DOUT to GND......................-0.3V to (V

DD

+0.3V)

REF, AIN1(AIN+), AIN2(AIN-) to GND..........-0.3V to (V

DD

+0.3V)

Maximum Current Into Any Pin ...........................................50mA

Continuous Power Dissipation (T

A

= +70°C)

8-Pin SOT23(derate 9.70mW/°C above T

A

= +70°C) ....777mW

Operating Temperature Ranges.........................-40°C to +85°C

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

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

DC ACCURACY (Note 1)

Resolution 10 Bits
Relative Accuracy (Note 2) INL ±1.0 LSB
Differential Nonlinearity DNL No missing codes over temperature ±1.0 LSB
Offset Error ±0.5 ±1.0 LSB
Gain Error (Note 3) ±1.0 ±2.0 LSB
Gain Temperature Coefficient ±0.8 ppm/°C

Channel-to-Channel Offset
Channel-to-Channel Gain Matching ±0.1 LSB

Input Common-Mode Rejection CMR VCM = 0V to VDD; zero scale input ±0.1 mV

DYNAMIC SPECIFICATIONS: (f
for MAX1087/MAX1089, 150ksps, f

Signal to Noise Plus Distortion SINAD 61 dB

Total Harmonic Distortion
(up to the 5

Spurious-Free Dynamic Range SFDR 70 dB

Full-Power Bandwidth -3dB point 1 MHz

Full-Linear Bandwidth SINAD>56dB 100 kHz

CONVERSION RATE

Conversion Time t

T/H Acquisition Time t

Aperture Delay 30 ns

Aperture Jitter <50 ps

Maximum Serial Clock Frequency f

Duty Cycle 30 70 %

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

th

harmonic)

(sine-wave) = 10kHz, VIN = 4.096Vp-p for MAX1086/MAX1088 or VIN = 2.5V

IN

= 8MHZ, AIN- = GND for MAX1088/MAX1089)

SCLK

THD -70 dB

CONV

ACQ

SCLK

±0.1 LSB

8 MHz

PP

3.7 µs

1.4 µs

MAX1086–MAX1089

150ksps, 10-Bit, 2-Channel Single-Ended, and

1-Channel True-Differential ADCs in SOT23

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +3.6V, V

REF

= +2.5V for MAX1087/MAX1089, or VDD

= +4.75V to +5.25V, V

REF

= +4.096V for MAX1086/MAX1088,

0.1µF capacitor at REF, f

SCLK

= 8MHz (50% duty cycle), AIN- = GND for MAX1088/MAX1089. TA= T

MIN

to T

MAX,

unless otherwise

noted. Typical values at T

A

= +25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

ANALOG INPUT

Input Voltage Range (Note 4)

Unipolar 0 V

Bipolar -V

Input Leakage Current C hannel not sel ected or conver si on stop p ed ±0.01 ±1 µA

Input Capacitance 34 pF

EXTERNAL REFERENCE INPUT

Input Voltage Range V

Input Current I

REF

REF

V

= +2.5V at 150ksps 16 30

REF

V

= +4.096V at 150ksps 26 45

REF

Acquisition/Between conversions ±0.01 ±1

DIGITAL INPUTS/OUTPUT (SCLK, CNVST, DOUT)

Input Low Voltage V

Input High Voltage V

Input Leakage Current I

Input Capacitance C

Output Low Voltage V

Output High Voltage V

Three-State Leakage Current I

Three-State Output Capacitance C

IL

IH

L

IN

OL

OH

L

OUT

I

= 2mA 0.4 V

SINK

I

= 4mA 0.8 V

SINK

I

SOURCE

= 1.5mA

CNVST = GND ±10 µA

CNVST = GND 15 pF

POWER REQUIREMENTS

Positive Supply Voltage V

DD

MAX1086/MAX1088 4.75 5.0 5.25

MAX1087/MAX1089 2.7 3.0 3.6

VDD = +3V

Positive Supply Current I

DD

VDD = +5V

Shutdown 0.2 5

Positive Supply Rejection PSR

VDD = 5V ±5%; full-scale input ±0.1 1.0

= +2.7V to +3.6V; full-scale input ±0.1 ±1.2

V

DD

f

f

f

f

f

f

f

f

=150ksps 245 350

SAMPLE

=100ksps 150

SAMPLE

=10ksps 15

SAMPLE

=1ksps 2

SAMPLE

=150ksps 320 400

SAMPLE

=100ksps 215

SAMPLE

=10ksps 22

SAMPLE

=1ksps 2.5

SAMPLE

REF

1.0

/2 V

REF

/2

REF

V

DD

+50mV

0.8 V

V

-1 V

DD

±0.1 µA

15 pF

V

DD

-0.5

V

V

µA

V

V

µA

mV

MAX1086–MAX1089

150ksps, 10-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23

4 _______________________________________________________________________________________

TIMING CHARACTERISTICS (Figures 1 and 2)

(VDD= +2.7V to +3.6V, V

REF

= +2.5V for MAX1087/MAX1089, or VDD= +4.75V to +5.25V, V

REF

= +4.096V for MAX1086/MAX1088,

0.1µF capacitor at REF, f

SCLK

= 8MHz (50% duty cycle); AIN- = GND for MAX1088/MAX1089. TA= T

MIN

to T

MAX,

unless otherwise

noted. Typical values at T

A

= +25°C.)

Note 1: Unipolar input.
Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after offset and gain errors have

been removed.

Note 3: Offset nulled.
Note 4: The absolute input range for the analog inputs is from GND to V

DD

.

Figure 1. Detailed Serial-Interface Timing Sequence

Figure 2. Load Circuits for Enable/Disable Times

PARAMETERS SYMBOL CONDITIONS MIN TYP MAX UNITS

SCLK Pulse Width High t

SCLK Pulse Width Low t

SCLK Fall to DOUT Transition t

SCLK Rise to DOUT Disable t

CNVST Rise to DOUT Enable t

CNVST Fall to MSB Valid t

CNVST Pulse Width t

CH

CL

C

DOT

DOD

DOE

DOV

CSW

= 30pF 60 ns

LOAD

C

= 30pF 100 500 ns

LOAD

C

= 30pF 80 ns

LOAD

C

= 30pF 3.7 µs

LOAD

38 ns

38 ns

30 ns

CNVST

SCLK

t

DOE

HIGH-Z

DOUT

DOUT

6kΩ

GND

a) HIGH -Z TO VOH, VOL TO VOH, AND VOH TO HIGH -Z

• • •

t

V

t

DOT

DD

C

GND

CH

L

t

CL

• • •

• • •

6kΩ

DOUT

C

L

a) HIGH -Z TO V

, VOH TO VOL, AND VOL TO HIGH -Z

OL

t

CSW

t

DOD

HIGH-Z

MAX1086–MAX1089

150ksps, 10-Bit, 2-Channel Single-Ended, and

1-Channel True-Differential ADCs in SOT23

_______________________________________________________________________________________ 5

Typical Operating Characteristics

(VDD= +3.0V, V

REF

= +2.5V for MAX1087/MAX1089 or VDD= +5.0V, V

REF

= +4.096V for MAX1086/MAX1088, 0.1µF capacitor at

REF, f

SCLK

= 8MHz, (50% Duty Cycle), AIN- = GND for MAX1088/1089, TA= +25°C, unless otherwise noted.)

INTEGRAL NONLINEARITY

vs. OUTPUT CODE

1.0

0.8

0.6

0.4

0.2

0

INL (LSB)

-0.2

-0.4

-0.6

-0.8

-1.0
0 400200 600 800 1000 1200

OUTPUT CODE

DIFFERENTIAL NONLINEARITY

vs. OUTPUT CODE

1.0

0.8

0.6

0.4

0.2

0

DNL (LSB)

-0.2

-0.4

-0.6

-0.8

-1.0
0 400 600200 800 1000 1200

OUTPUT CODE

380

330

280

SUPPLY CURRENT ( µA)

230

180

2.7 3.73.2 4.2 4.7 5.2

MAX1087/MAX1089

MAX1086-9 toc01

MAX1086/MAX1088

MAX1086-9 toc04

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

VDD (V)

INTEGRAL NONLINEARITY

vs. OUTPUT CODE

1.0

0.8

0.6

0.4

0.2

0

INL (LSB)

-0.2

-0.4

-0.6

-0.8

-1.0
0 400200 600 800 1000 1200

SUPPLY CURRENT

vs. SAMPLING RATE

1000

MAX1087/MAX1089

100

10

SUPPLY CURRENT (µA)

1

0.1

0.001 10 1000

MAX1086-9 toc07

1.0

SAMPLING RATE (ksps)

MAX1086/MAX1088

OUTPUT CODE

SHUTDOWN CURRENT (nA)

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0

2.7 3.73.2 4.2 4.7 5.2

1.0

0.8

0.6

MAX1086-9 toc02

0.4

0.2

0

DNL (LSB)

-0.2

-0.4

-0.6

-0.8

-1.0
0 400 600200 800 1000 1200

1000

MAX1086/MAX1088

MAX1086-9 toc05

100

10

SUPPLY CURRENT (µA)

1

0.1

0.001 10 10001.0

SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE

VDD (V)

DIFFERENTIAL NONLINEARITY

vs. OUTPUT CODE

MAX1087/MAX1089

MAX1086-9 toc03

OUTPUT CODE

SUPPLY CURRENT

vs. SAMPLING RATE

MAX1086-9 toc06

SAMPLING RATE (ksps)

MAX1086-9 toc08