SPT7760
8-BIT, 1 GSPS, FLASH A/D CONVERTER
OCTOBER 2002
FEATURES
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1:2 Demuxed ECL compatible outputs
Wide input bandwidth – 900 MHz
Low input capacitance – 15 pF
Metastable errors reduced to 1 LSB
Monolithic for low cost
Gray code output
APPLICATIONS
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Digital oscilloscopes
Transient capture
Radar, EW, ECM
Direct RF down-conversion
GENERAL DESCRIPTION
The SPT7760 is a full parallel (flash) analog-to-digital con-
verter capable of digitizing full scale (0 to –2 V) inputs into
eight-bit digital words at an update rate of 1 GSPS. The
ECL-compatible outputs are demultiplexed into two sepa-
rate output banks, each with differential data ready outputs
to ease the task of data capture. The SPT7760’s wide input
bandwidth and low capacitance eliminate the need for ex-
ternal track-and-hold amplifiers for most applications. A
proprietary decoding scheme reduces metastable errors
to the 1 LSB level. The SPT7760 operates from a single
–5.2 V supply, with a nominal power dissipation of 5.5 W.
The SPT7760 is available in an 80-lead surface-mount
MQuad package over the industrial temperature range
(–25
°C
to +85
°C).
BLOCK DIAGRAM
V
RT
Analog
Input
Preamp
Comparator
256
CLK CLK
CLOCK
BUFFER
DEMUX
CLOCK
BUFFER
255
D8
(OVR)
D7
(MSB)
D6
DRB (DATA READY)
D8B
D7B
D6B
D5B
D4B
D3B
D2B
DRB (DATA READY)
D8B (OVR)
D7B (MSB)
D5B
BANK B
BANK A
152
ECL Output Buffers And Latches
151
256 TO 8 Bit Decoder
With Metastable Error Correction
D6B
D4B
D3B
D2B
D1B
D0B (LSB)
DRA (DATA READY)
DRA (DATA READY)
D8A (OVR)
D7A (MSB)
D6A
D5A
D4A
D3A
D2A
D1A
D0A (LSB)
D5
1:2 DEMULTIPLEXER
128
D1B
D0B
V
RM
127
D4
D8A
D7A
D6A
D5A
D4A
D3A
D2A
D1A
D0A
64
D3
63
D2
2
D1
1
D0
(LSB)
V
RB
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
