1 Features

1• 1.25-MHz Sample Rate Serial Device

• 10-Bit Resolution (ADS7887)

• 8-Bit Resolution (ADS7888)

• Zero Latency

• 25-MHz Serial Interface

• Supply Range: 2.35 V to 5.25 V

• Typical Power Dissipation at 1.25 MSPS:

– 3.8 mW at 3-V VDD

– 8 mw at 5-V VDD

• ±0.35 LSB INL, DNL (ADS7887)

• ±0.15 LSB INL, ±0.1 LSB DNL (ADS7888)

• 61 dB SINAD, –84 dB THD (ADS7887)

• 49.5 dB SINAD, –67.5 dB THD (ADS7888)

• Unipolar Input Range: 0 V to VDD

• Power-Down Current: 1 μA

• Wide Input Bandwidth: 15 MHz at 3 dB

• 6-Pin SOT23 and SC70 Packages

2 Applications

• Base Band Converters in Radio Communication

• Motor Current and Bus Voltage Sensors in Digital

Drives

• Optical Networking (DWDM, MEMS-Based

Switching)

• Optical Sensors

• Battery-Powered Systems

• Medical Instrumentations

• High-Speed Data Acquisition Systems

• High-Speed Closed-Loop Systems

3 Description

The ADS7887 device is a 10-bit, 1.25-MSPS, analogto-

digital converter (ADC), and the ADS7888 device

is a 8-bit, 1.25-MSPS ADC. These devices include a

capacitor-based SAR A/D converter with inherent

sample and hold. The serial interface in each device

is controlled by the CS and SCLK signals for glueless

connections with microprocessors and DSPs. The

input signal is sampled with the falling edge of CS,

and SCLK is used for conversion and serial data

output.

The devices operate from a wide supply range from

2.35 V to 5.25 V. The low power consumption of the

devices make them suitable for battery-powered

applications. The devices also include a powersaving,

power-down feature for when the devices are

operated at lower conversion speeds.

The high level of the digital input to the device is not

limited to device VDD. This means the digital input can

go as high as 5.25 V when device supply is 2.35 V.

This feature is useful when digital signals are coming

from other circuit with different supply levels. Also this

relaxes restriction on power-up sequencing.

The ADS7887 and ADS7888 are available in 6-pin

SOT-23 and SC70 packages and are specified for

operation from –40°C to 125°C.