SPT1175
8-BIT, 20 MSPS CMOS A/D CONVERTER
FEATURES
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20 MSPS Maximum Conversion Rate
Internal Sample-and-Hold Function
90 mW Power Dissipation
Internal Voltage Reference
Single +5.0 V Power Supply
Three-State TTL-Outputs
CMOS Compatible Clock
APPLICATIONS
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Video Digitizing
Image Scanners
Personal Computer Video
Medical Ultrasound
Multimedia
Digital Television
GENERAL DESCRIPTION
The SPT1175 is a CMOS two-step A/D converter capable of
digitizing full scale analog input signals into 8-bit digital words
at a sample rate of 20 MSPS.
For most applications, no external sample-and-hold or
video driving amplifiers are required due to the device's
narrow aperture time, wide bandwidth, and low input ca-
pacitance.
The SPT1175 operates from a single +5.0 V power supply
and has an internal voltage reference which eliminates the
need for external reference circuitry. All digital inputs are
CMOS compatible and the tri-state outputs are TTL-compat-
ible. The SPT1175 is ideal for most video and image pro-
cessing applications that require low power dissipation and
low cost. The SPT1175 is available in 24-lead plastic SOIC,
plastic DIP, and PLCC packages over the commercial tem-
perature range (0 to +70
°C).
It is also available in die form.
BLOCK DIAGRAM
V
RB
V
RBS
DV
DD
DGND
OE
Coarse
Sampling
Amplifier
Latch
Encoder
DØ (LSB)
D1
Error
Correction
Circuit
Data
Latches
and
3-State
Output
Buffer
D2
D3
D4
D5
D6
VIN
Reference Matrix
Fine
Sampling
Amplifier
Fine
Sampling
Amplifier
D7 (MSB)
Encoder
Analog
Mux
Latch
Timing
Generator
CLK
V
RT
V
RTS
AGND AV
D
DV
DD
AGND