ANALOG DEVICES ADAS1127 Service Manual

S/H

OR0

S/H

OR31

AN0

AN31

S/H

OR32

S/H

OR63

AN32

AN63

KGND

ADCL

+ –

DATA

PROCESSING

LVDS/CMOS INTERFACE

TEMPERATURE

OR[0:63]

ADAS1127

2.5V 3.3V

TO NEXT

SDI

SDO

BUFP BUFN

REF

2.048V

SDI

FROM

SDO

SDI

CONFIGURATION

SCK CS

DOUTx CLKx SYNC

IOVDD

RESET

IOGND

TO ALL ADCs

2.5V

FROM DOUT

OF OT HE R ADCs

FPGA

VIO

08785-001

64-Channel, 24-Bit Current-to-Digital ADC

FEATURES

64-channel, low level current-to-digital converter Up to 24-bit resolution Up to 19.7 kSPS (50.7 µs integration time) Simultaneous sampling Ultralow noise (down to 0.4 fC [2500e

−

]) User-adjustable full-scale range INL: ±0.025% of reading ±0.75 ppm of FSR Very low power dissipation: 6.25 mW/channel LVDS self-clocked serial data interface SPI configuration registers (daisy-chain) On-board temperature sensor and reference buffer 10 mm × 10 mm, mini-BGA package Low cost external components Support tools

Evaluation board Reference design with reference layout FPGA Verilog code

APPLICATIONS

Medical, industrial, and security CT scanner data acquisition Photodiode sensors Dosimetry and radiation therapy systems Optical fiber power monitoring X-ray detection systems High channel-count data acquisition systems (current or

voltage inputs)

FUNCTIONAL BLOCK DIAGRAM

ADAS1127

GENERAL DESCRIPTION

The ADAS1127 is a 64-channel, current-to-digital, analog-todigital converter (ADC). It contains 64 low power, low noise, low input current integrators, simultaneous sample-and-holds, and a high speed, high resolution ADCs with configurable sampling rate and resolutions up to 24 bits.

All converted channel results are output on a single LVDS selfclocked serial interface, which reduces external hardware.

An SPI-compatible serial interface allows configuration of the ADC using the SDI input. The SDO output allows the user to daisy-chain several ADCs on a single, 3-wire bus. The ADAS1127 uses the separate supply IOVDD to reduce the digital noise effect on the conversions.

The ADAS1127 is in a 10 mm × 10 mm, mini-BGA package.

Rev. SpA

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of t heir respective owners.

Figure 1.