鈥?/div>
Monolithic 28 MSPS Analog-to-Digital Converter
170 mW Power Dissipation
On-Chip Track-and-Hold
Single +5 V Power Supply
TTL/CMOS Outputs
5 pF Input Capacitance
Selectable +3 V or +5 V Logic I/O
APPLICATIONS
鈥?All High-Speed Applications Where
Low Power Dissipation Is Required
鈥?Video Imaging
鈥?Medical Imaging
鈥?IR Imaging
鈥?Digital Communications
GENERAL DESCRIPTION
The SPT7937 is a 12-bit monolithic, low-cost, low-power
analog-to-digital converter capable of minimum sample
rates of 28 MSPS. The SPT7937 has incorporated propri-
etary parallel SAR circuit design and CMOS processing
technologies to achieve its advanced performance.The on-
chip track-and-hold function assures very good dynamic
performance without the need for external components.
Power dissipation is extremely low at only 170 mW typical at
28 MSPS with a power supply of +5.0 V. The digital outputs
are +3 V or +5 V, and are user selectable. Inputs and out-
puts are TTL/CMOS compatible to interface with TTL/
CMOS logic systems. Output data format is straight binary.
The SPT7937 is available in a 28-lead SSOP package over
the industrial temperature range.
BLOCK DIAGRAM
ADC Section 1
A
IN
1:18
Mux
T/H
Auto-
Zero
CMP
13-Bit
SAR
13
13
D12 Out of Range
D11 (MSB)
D10
P1
P2
CLK In
Timing
P17
and
Control
P18
DAC
D9
ADC Section 2
13
13-Bit
18:1
Mux/
Error
Correction
D8
D7
D6
D5
D4
D3
D2
D1
Reference Ladder
D脴 (LSB)
.
.
.
.
.
.
.
.
.
.
.
.
ADC Section 17
ADC Section 18
T/H
Auto-
Zero
CMP
13
13-Bit
SAR
13
DAC
13
V
RHF
V
RHS
V
RLS
V
RLF
Signal Processing Technologies, Inc.
4755 Forge Road, Colorado Springs, Colorado 80907, USA
Phone: (719) 528-2300 FAX: (719) 528-2370 Website: http://www.spt.com E-Mail: sales@spt.com