SPT
SIGNAL PROCESSING TECHNOLOGIES
SPT7760
8-BIT, 1 GSPS FLASH A/D CONVERTER
FEATURES
• 1:2 Demuxed ECL Compatible Outputs
• Wide Input Bandwidth - 900 MHz
• Low Input Capacitance - 15 pF (MQUAD)
• Metastable Errors Reduced to 1 LSB
• Monolithic for Low Cost
• Gray Code Output
GENERAL DESCRIPTION
The SPT7760 is a full parallel (flash) analog-to-digital converter capable of digitizing full scale (0 to -2 V) inputs into
eight-bit digital words at an update rate of 1 GSPS. The ECLcompatible outputs are demultiplexed into two separate
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 external track-and-hold amplifiers for most applications. A propri-
CLKCLK
BLOCK DIAGRAM
CLOCK
Analog
V
RT
Input
Preamp Comparator
256
BUFFER
APPLICATIONS
• Digital Oscilloscopes
• Transient Capture
• Radar, EW, ECM
• Direct RF Down-Conversion
etary 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 80L surface-mount MQUAD
package over the industrial temperature range. Contact the
factory for availability of die and /883 versions.
DEMUX
CLOCK
BUFFER
255
152
151
128
V
RM
V
RB
127
64
63
2
1
D8
(OVR)
D7
(MSB)
D6
D5
D4
256 TO 8 BIT DECODER
D3
WITH METASTABLE ERROR CORRECTION
D2
D1
DO
(LSB)
D8B
D7B
•
•
D5B
•
•
D2B
D1B
D0B
D8
D7
•
•
•
1:2 DEMULTIPLEXER
D5
•
•
•
D2
D1
D0
DRB (DATA READY)
DRB (DATA READY)
D8B (OVR)
D7B (MSB)
D6B
D5B
D4B
D3B
D2B
D1B
D0B (LSB)
DRA (DATA READY)
DRA (DATA READY)
D8A (OVR)
D7A (MSB)
D6A
D5A
ECL OUTPUT BUFFERS AND LATCHES
D4A
D3A
D2A
D1A
D0A (LSB)
Signal Processing Technologies, Inc.
Phone: (719) 528-2300 FAX: (719) 528-2370 Website: http://www.spt.com E-Mail: sales@spt.com
4755 Forge Road, Colorado Springs, Colorado 80907, USA
ABSOLUTE MAXIMUM RATINGS (Beyond which damage may occur)1 25 °C
Supply Voltages
Negative Supply Voltage (V
Ground Voltage Differential............................. .-0.5 to +0.5 V
TO GND) ......... .-7.0 to +0.5 V
EE
Output
Digital Output Current ........................................ 0 to -28 mA
Temperature
Input Voltage
Analog Input Voltage........................................ +0.5 V to V
Reference Input Voltage .................................. +0.5 V to V
Digital Input Voltage ......................................... +0.5 V to V
Reference Current VRT to VRB.................................... 35 mA
EE
EE
EE
Operating Temperature, ambient .......................-25 to +85 °C
case ...................................+125 °C
junction............................... +150 °C
Lead Temperature, (soldering 10 seconds). ............. +300 °C
Storage Temperature......................................-65 to +150 °C
Notes: 1. Operation at any Absolute Maximum Rating is not implied. See Electrical Specifications for proper nominal applied condi-
tions in typical applications.
ELECTRICAL SPECIFICATIONS
TJ = TC = TA = +25 °C , VEE=-5.2 V, VRB=-2.00 V, VRM=-1.0 V, VRT=0.00 V, f
TEST TEST SPT7760A SPT7760B
PARAMETERS CONDITIONS LEVEL MIN TYP MAX MIN TYP MAX UNITS
Resolution 8 8 Bits
DC Accuracy (+25 °C)
Integral Nonlinearity f
Differential Nonlinearity f
= 100 kHz I -1.0 +1.0 -1.5 +1.5 LSB
CLK
= 100 kHz I -0.85 +0.95 -0.95 +1.5 LSB
CLK
No Missing Codes Guaranteed Guaranteed
Analog Input
Input Voltage Range I V
Input Bias Current V
=0 V I .75 2.0 .75 2.0 mA
IN
Input Resistance V 15 15 kΩ
Input Capacitance Over Full Input Range V 15 15 pF
Input Bandwidth
Small Signal V 900 900 MHz
Large Signal V 500 500 MHz
Offset Error V
Offset Error V
RT
RB
Input Slew Rate V 5 5 V/ns
Clock Synchronous
Input Currents V 2 2 µA
Reference Input
Ladder Resistance I 60 80 60 80 Ω
Reference Bandwidth V 30 30 MHz
Timing Characteristics
Maximum Sample Rate I 1 1 GHz
Aperture Jitter V 2 2 ps
Acquisition Time V 250 250 ps
CLK to Data Ready Delay IV 0.9 1.4 1.9 0.9 1.4 1.9 ns
Clock to Data Delay IV 1.25 1.75 2.25 1.25 1.75 2.25 ns
Dynamic Performance
Signal-To-Noise Ratio
(without Harmonics)
f
= 50 MHz I 45 43 dB
IN
f
= 250 MHz I 43 41 dB
IN
Total Harmonic Distortion
f
= 50 MHz I -44 -42 dBc
IN
f
= 250 MHz I -36 -34 dBc
IN
=1 GHz, Duty Cycle=50%, unless otherwise specified.
clk
RB
V
RT
V
RB
VRTV
I -30 +30 -30 +30 mV
I -30 +30 -30 +30 mV
SPT
SPT7760
2 3/10/97
ELECTRICAL SPECIFICATIONS
TJ = TC = TA = +25 °C , VEE=-5.2 V, VRB=-2.00 V, VRM=-1.0 V, VRT=0.00 V, f
TEST TEST SPT7760A SPT7760B
PARAMETERS CONDITIONS LEVEL MIN TYP MAX MIN TYP MAX UNITS
Dynamic Performance
Signal-to-Noise and Distortion
f
= 50 MHz I 42 40 dB
IN
f
= 250 MHz I 35 33 dB
IN
Spurious Free Dynamic Range
f
= 50 MHz I 47 43 dB
IN
f
= 250 MHz I 39 35 dB
IN
Digital Inputs
Input High Voltage
(CLK, NCLK) I -1.1 -0.7 -1.1 -0.7 V
Input Low Voltage
(CLK, NCLK) I -1.8 -1.5 -1.8 -1.5 V
Clock Pulse Width High (t
Clock Pulse Width Low (t
Digital Outputs
Logic "1" Voltage I -1.1 -0.9 -1.1 -0.9 V
Logic "0" Voltage I -1.8 -1.5 -1.8 -1.5 V
Rise Time 20% to 80% V 450 450 ps
Fall Time 20% to 80% V 450 450 ps
Power Supply Requirements
Voltage V
Current I
Power Dissipation I 5.5 6.25 5.5 6.25 W
EE
EE
) I 0.5 0.4 0.5 0.4 ns
PWH
) I 0.5 0.4 0.5 0.4 ns
PWL
=1 GHz, Duty Cycle=50%, unless otherwise specified.
clk
IV -4.95 -5.2 -5.45 -4.95 -5.2 -5.45 V
I 1.05 1.2 1.05 1.2 A
Typical Thermal Impedance: θJC = +4 °C/W.
TEST LEVEL CODES
All electrical characteristics are subject to the
following conditions:
All parameters having min/max specifications
are guaranteed. The Test Level column indicates the specific device testing actually performed during production and Quality Assurance inspection. Any blank section in the data
column indicates that the specification is not
tested at the specified condition.
Unless otherwise noted, all tests are pulsed
tests; therefore, TJ = TC = TA.
TEST LEVEL
I
II
III
IV
V
VI
TEST PROCEDURE
100% production tested at the specified temperature.
100% production tested at TA=25 °C, and sample
tested at the specified temperatures.
QA sample tested only at the specified temperatures.
Parameter is guaranteed (but not tested) by design
and characterization data.
Parameter is a typical value for information purposes
only.
100% production tested at TA = 25 °C. Parameter is
guaranteed over specified temperature range.
SPT
SPT7760
3 3/10/97