Fairchild Semiconductor KH231 Datasheet

Features

■

165MHz closed-loop – -3dB bandwidth

■

15ns settling to 0.05%

■

1mV input offset voltage, 10µV/°C drift

■

100mA output current

■

Excellent AC and DC linearity

■

Direct replacement for CLC231

Applications

■

Driving flash A/D converters

■

Precision line driving
(a gain of 2 cancels matched-line losses)

■

DAC current-to-voltage conversion

■

Low-power, high-speed applications (50mW @ ±5V)

General Description

The KH231 Buffer/Amplifier is a wideband operational
amplifier designed specifically for high-speed, low­gain applications. The KH231 is based on a current
feedback op amp topology-a unique design that both
eliminates the gain-bandwidth tradeoff and permits
unprecedented high-speed performance. (See table below.)

The KH231 Buffer/Amplifier is the ideal design alter­native to low precision open-loop buffers and oscillation­prone conventional op amps. The KH231 offers precise
gains from ±1.000 to ±-5.000 and linearity that is a
true 0.1%-even for demanding 50

Ω loads. Open-loop

buffers, on the other hand, offer a nominal gain of

0.95 ±0.03 and a linearity of only 3% for typical loads.
A buffer’s settling time may look impressive but it is
usually specified at unrealistically large load resis­tances or when the effects of thermal tail are not
included; the KH231 Buffer/Amplifier settles to 0.05%
in 15ns-while driving a 100Ω load.

Offsets and drifts, usually a low priority in conven­tional high-speed op amp designs, were not ignored
in the KH231; the input offset voltage is typically 1mV
and input offset voltage drift is only 10µV/°C. The
KH231 is stable and oscillation-free across the entire
gain range and since it’s internally compensated, the
user is saved the trouble of designing external com­pensation networks and having to “tweak” them in
production. The absence of a gain-bandwidth trade­off in the KH231 allows performance to be predicted
easily; the table below shows how the bandwidth is
affected very little by changing the gain setting.

The KH231 is constructed using thin film resistor/bipolar
transistor technology, and is available in the following
versions:

The KH231 is constructed using thin film resistor/bipolar
transistor technology, and available in these versions:

KH231AI -25°C to +85°C 12-pin TO-8 can
KH231AK -55°C to +125°C 12-pin TO-8 can, features

burn-in & hermetic testing

KH231AM -55°C to +125°C 12-pin TO-8 can,

environmentally
screened and electrically
tested to MIL-STD-883

KH231HXC -55°C to +125°C SMD#: 5962-8959401HXC
KH231HXA -55°C to +125°C SMD#: 5962-8959401HXA

KH231

Fast Settling, Wideband Buffer/Amplifier (Av= ±1 to ±5)

www.fairchildsemi.com

REV. 1A February 2001

Small Signal Pulse Response

Output Voltage (400mV/div)

Time (5ns/div)

Av = -2

Av = 2

Supply
Voltage

8

Adjust

7

GND

9

-V

CC

2

Adjust

3

GND

1

+V

CC

6

V+

5

V-

4

NC

10

-V

CC

V

o

+V

CC

11

12

4

4

Collector
Supply

Output

Collector
Supply

Supply
Voltage

I

CC

Adjust

I

CC

Adjust

Case

ground

Non-Inverting

Input

Inverting

Input

Not

Connected

Case

ground

+

-

Bottom View

Pins 2 and 8 are used to adjust the supply current or to adjust the off­set voltage (see text). These pins are normally left unconnected.

Typical Performance

Gain Setting

Parameter 125-1-2-5Units

-3dB bandwidth 180 165 130 165 150 115 MHz
rise time (2V) 1.8 2.0 2.5 2.0 2.2 2.9 ns
slew rate 2.5 3.0 3.0 3.0 3.0 3.0 V/ns
settling time (to 0.1%) 12 12 12 12 12 15 ns

2 REV. 1A February 2001

DATA SHEET KH231

PARAMETERS CONDITIONS TYP MIN & MAX RATINGS UNITS SYM

Ambient Temperature KH231AI +25°C -25°C +25°C +85°C

Ambient Temperature KH231AK/AM/HXC/HXA +25°C -55°C +25°C +125°C

FREQUENCY DOMAIN RESPONSE

✝ -3dB bandwidth (note 2) V

o

≤2V

pp

165 >145 >145 >120 MHz SSBW

large-signal bandwidth V

o

≤10V

pp

95 >80 >80 >60 MHz FPBW

gain flatness (note 2) V

o

≤2V

pp

✝ peaking 0.1 to 50MHz 0.1 <0.6 <0.3 <0.6 dB GFPL
✝ peaking >50MHz 0.1 <1.5 <0.3 <0.8 dB GFPH
✝ rolloff at 100MHz 0.4 <0.6 <0.6 <1.0 dB GFR

group delay to 100MHz 3.5 ± 0.5 –––ns GD
linear phase deviation to 100MHz 0.5 <2.0 <2.0 <2.0 ° LPD
reverse isolation

non-inverting 53 >43 >43 >43 dB RINI
inverting 36 >26 >26 >26 dB RIIN

TIME DOMAIN RESPONSE

rise and fall time 2V step 2.0 <2.4 <2.3 <2.7 ns TRS

10V step 5.0 <7.0 <6.5 <6.5 ns TRL

settling time to 0.05% 5V step 15 –––ns TS

to 0.1% 2.5V step 12 <22 <17 <22 ns TSP
overshoot 5V step 5 <15 <10 <15 % OS
slew rate (overdriven input) 3.0 >2.5 >2.5 >1.8 V/ns SR
overload recovery <1% error

<50ns pulse, 200% overdrive 120 –––ns OR

NOISE AND DISTORTION RESPONSE

✝ 2nd harmonic distortion 0dBm, 20MHz -55 <-47 <-47 <-47 dBc HD2
✝ 3rd harmonic distortion 0dBm, 20MHz -59 <-47 <-47 <-47 dBc HD3

equivalent input noise

noise floor >5MHz -153 <-150 <-150 <-150 dBm(1Hz) SNF
integrated noise 5MHz to 200MHz 70 <100 <100 <100

µVrms INV

STATIC, DC PERFORMANCE

* input offset voltage 1 <4.0 <2.0 <4.5 mV VIO

average temperature coefficient 10 <25 <25 <25

µV/°C DVIO

* input bias current non-inverting 5.0 <29 <21 <31

µA IBN

average temperature coefficient 50 <125 <125 <125 nA/°C DIBN

* input bias current inverting 10 <31 <15 < 35

µA IBI

average temperature coefficient 125 <200 <200 <200 nA/°C DIBI

* power supply rejection ratio 50 >45 >45 >45 dB PSRR

common mode rejection ratio 46 >40 >40 >40 dB CMRR

* supply current no load 18 <22 <22 <22 mA ICC

MISCELLANEOUS PERFORMANCE

non-inverting input resistance DC 400 >100 >200 >400 kΩ RIN
non-inverting input capacitance 1.3 <2.5 <2.5 <2.5 pF CIN
output impedance @ 100MHz 5, 37 –––

Ω, nH RO

output voltage range no load ±12 >±11 >±11 >±11 V VO

Min/max ratings are based on product characterization and simulation. Individual parameters are tested as noted. Outgoing quality levels are
determined from tested parameters.

Absolute Maximum Ratings Recommended Operating Conditions

V

CC

±20V V

CC

±5V to ±15V

I

o

±100mA I

o

±75mA

common mode input voltage, V

o

(see Vcmand V

o

common mode input voltage ±(|VCC| -5)V

limits plot on page 3) gain range ±1 to ±5
differential input voltage ±3V
thermal resistance (see thermal model)
junction temperature +175°C
operating temperature AI: -25°C to +85°C

AK/AM: -55°C to +125°C
storage temperature -65°C to +150°C
lead temperature (soldering 10s) +300°C

KH231 Electrical Characteristics

(

T

A

= +25°C,

A

v

= +2V, VCC= ±15V, RL= 100Ω, Rf= 250Ω; unless specified)

note 1: * AI/AK/AM/HXC/HXA 100% tested at +25°C

✝ AK/AM/HXC/HXA 100% tested at +25°C and sample

tested at -55°C and +125°C

✝ AI sample tested at +25°C

note 2: The output amplitude used in testing is 0.63Vpp. Performance

is guaranteed for conditions listed.

note 3: In the noninverting configuration, care should be taken when

choosing Ri, the input impedance setting resistor; bias
currents of typically 5µA but as high as 24µA can create an
input signal large enough to cause overload. It is therefore
recommended that Ri< (VCC/Av)/24µA.

note 4: These ratings protect against damage to the input stage

caused by saturation of either the input or output stages at
lower supply voltages, and against exceeding transistor
collector-emitter breakdown ratings at high supply voltages.
V

out(max)

is calculated by assuming no output saturation.
Saturation is allowed to occur up to this calculated level of
V

out.Vcm

is defined as the voltage at the non-inverting

input, pin 6.