DDC264 Datasheet, PDF (1/26 Pages) Texas Instruments – 64-Channel, Current-Input Analog-to-Digital Converter

DDC264
DDC264
www.ti.com
64-Channel, Current-Input
Analog-to-Digital Converter
Check for Samples: DDC264
SBAS368C – MAY 2006 – REVISED JULY 2011
FEATURES
1
•2 Single-Chip Solution to Directly Measure 64
Low-Level Currents
• Proven High-Precision, True Integrating
Architecture with 100% Charge Collection
• Easy Upgrade for Existing DDC Family
Applications
• Very Low Power: 3mW/channel
• Extremely Linear:
INL = ±0.025% of Reading ±1.0ppm of FSR
• Low Noise: 6.3ppm of FSR
• Adjustable Full-Scale Range
• Adjustable Speed
– Data Rates up to 6kSPS with 20-bit
Performance
– Integration Times as low as 160μs
• Daisy-Chainable Serial Interface
• In-Package Bypass Capacitors Simplify PCB
Design
APPLICATIONS
• CT Scanner DAS
• Photodiode Sensors
• X-Ray Detection Systems
DESCRIPTION
The DDC264 is a 20-bit, 64-channel, current-input
analog-to-digital (A/D) converter. It combines both
current-to-voltage and A/D conversion so that 64
separate low-level current output devices, such as
photodiodes, can be directly connected to its inputs
and digitized.
For each of the 64 inputs, the DDC264 uses the
proven dual switched integrator front-end. This
configuration allows for continuous current
integration: while one integrator is being digitized by
the onboard A/D converter, the other is integrating
the input current. This architecture provides both a
very stable offset and a loss-less collection of the
input current. Adjustable integration times range from
160μs to 1s, allowing currents from fAs to μAs to be
continuously measured with outstanding precision.
The DDC264 has a serial interface designed for
daisy-chaining in multi-device systems. Simply
connect the output of one device to the input of the
next to create the chain. Common clocking feeds all
the devices in the chain so that the digital overhead
in a multi-DDC264 system is minimal.
The DDC264 uses a +5V analog supply and a +2.7V
to +3.6V digital supply. Bypass capacitors within the
DDC264 package help minimize the external
component requirements. Operating over the
temperature range of 0°C to +70°C, the DDC264
BGA-100 package is offered in two versions: the
DDC264C for low-power applications, and the
DDC264CK when higher speeds are required.
AVDD VREF
DVDD
0.2mF
0.3mF
0.1mF
IN1
Dual
Switched
Integrator
IN2
Dual
Switched
Integrator
IN3
Dual
Switched
Integrator
IN4
Dual
Switched
Integrator
DS
ADC
DS
ADC
Configuration
and
Control
CLK
CONV
DIN_CFG
CLK_CFG
RESET
DVALID
IN61
Dual
Switched
Integrator
IN62
Dual
Switched
Integrator
DS
ADC
Serial
Interface
DCLK
DOUT
IN63
Dual
Switched
Integrator
IN64
Dual
Switched
Integrator
DS
ADC
DIN
AGND
DGND
Protected by US Patent #5841310
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006–2011, Texas Instruments Incorporated