2.7 V to 5.25 V, Micropower, 2-Channel,

125 kSPS, 12-Bit ADC in 8-Lead MSOP

AD7887

Rev. D

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FEATURES

Flexible power/throughput rate management

Shutdown mode: 1 μA max

One or two single-ended inputs

Serial interface: SPI®/QSPI™/MICROWIRE™/DSP compatible

8-lead narrow SOIC and MSOP packages

APPLICATIONS

Battery-powered systems (personal digital assistants,

medical instruments, mobile communications)

Instrumentation and control systems

High speed modems

FUNCTIONAL BLOCK DIAGRAM

SAR + ADC

CONTROL LOGIC

GND

AIN0

SCLK

DOUT

DIN

AD7887

CS

T/H

I/P

MUX

BUF

CHARGE

REDISTRIBUTION

DAC

COMP

AIN1/

SOFTWARE

CONTROL

LATCH

2.5V

REF

SPORT

Figure 1.

GENERAL DESCRIPTION

The AD7887 is a high speed, low power, 12-bit analog-to-digital

converter (ADC) that operates from a single 2.7 V to 5.25 V

power supply. The AD7887 is capable of 125 kSPS throughput

rate. The input track-and-hold acquires a signal in 500 ns and

features a single-ended sampling scheme. The output coding for

the AD7887 is straight binary, and the part is capable of

converting full power signals of up to 2.5 MHz.

The AD7887 can be configured for either dual- or single-channel

operation via the on-chip control register. There is a default

single-channel mode that allows the AD7887 to be operated as a

read-only ADC. In single-channel operation, there is one

external reference to provide the reference voltage for the part.

function, providing a second analog input channel. In this case,

a result, the input voltage range on both the AIN0 and AIN1

CMOS construction ensures low power dissipation of typically

2 mW for normal operation and 3 μW in power-down mode.

The part is available in an 8-lead, 0.15-inch-wide narrow body

SOIC and an 8-lead MSOP package.

PRODUCT HIGHLIGHTS

1.

Smallest 12-bit dual-/single-channel ADC; 8-lead MSOP

package.

2.

Lowest power 12-bit dual-/single-channel ADC.

3.

Flexible power management options, including automatic

power-down after conversion.

4.

Read-only ADC capability.

5.

6.

Versatile serial input/output port (SPI/QSPI/MICROWIRE/

DSP compatible).