OPA687 Datasheet, PDF (1/17 Pages) Burr-Brown (TI) – Wideband, Ultra-Low Noise, Voltage Feedback OPERATIONAL AMPLIFIER With Power Down

OPA687
OPA687
www.ti.com
TM _{Wideband, Ultra-Low Noise,}
Voltage Feedback OPERATIONAL AMPLIFIER
With Power Down
FEATURES
q HIGH GAIN BANDWIDTH: 3.8GHz
q LOW INPUT VOLTAGE NOISE: 0.95nV/√Hz
q VERY LOW DISTORTION: –95dBc (5MHz)
q LOW DISABLED POWER: 2mW
q VERY HIGH SLEW RATE: 900V/µs
q STABLE FOR G ≥ 12
DESCRIPTION
The OPA687 combines a very high gain bandwidth and
large signal performance with an ultra-low input noise
voltage (0.95nV/√Hz) while dissipating only 18mA sup-
ply current. Where power savings is paramount, the
OPA687 also includes an optional power down pin that,
when pulled low, will disable the amplifier and decrease
the quiescent current to only 1% of its powered up value.
This optional feature may be left disconnected to insure
normal amplifier operation when no power-down is re-
quired.
The combination of low input voltage and current noise,
along with a 3.8GHz gain bandwidth product, make the
OPA687 an ideal amplifier for wideband transimpedance
APPLICATIONS
q LOW DISTORTION ADC DRIVER
q OC-3 FIBER OPTIC RECEIVER
q LOW NOISE DIFFERENTIAL AMPLIFIERS
q EQUALIZING RECEIVERS
q ULTRASOUND CHANNEL AMPLIFIERS
q IMPROVED REPLACEMENT FOR THE
CLC425
stages. As a voltage gain stage, the OPA687 is opti-
mized for a flat frequency response at a gain of +20 and
is guaranteed stable down to gains of +12. New external
compensation techniques allows the OPA687 to be used
at any inverting gain with excellent frequency response
control. Using this compensation can give an extremely
high dynamic range ADC driver to support > 40MSPS
12- and 14-bit converters.
OPA687 RELATED PRODUCTS
SINGLES
DUAL
INPUT NOISE GAIN BANDWIDTH
VOLTAGE (nV/√Hz) PRODUCT (MHz)
OPA642
—
2.7
OPA643
—
2.3
OPA686 OPA2686
1.3
210
800
1600
50Ω Source
< 6dB
Noise
Figure
+5V
V_CM
20Ω
100Ω
OPA687
1.7pF
–5V
1:2
39pF
850Ω
39pF
850Ω
+5V
100Ω
1.7pF
20Ω
OPA687
V_CM
–5V
Ultra-High Dynamic Range
Differential Input ADC Driver
+5V
V_IN+
80pF
ADS852
14-Bit
65MSPS
V_IN–
80pF
–60
–65
4Vp-p
–70
–75
2Vp-p
–80
–85
0
5 10 15 20 25 30 35 40 45 50
Center Frequency (MHz)
Measured 2-Tone, 3rd-Order Distortion for
Differential ADC Driver.
Copyright © 1998, Texas Instruments Incorporated
SBOS065A
Printed in U.S.A. January, 2001