Datasheet

4
LT1251/LT1256
SIG AL A PLIFIER DC CHARACTERISTICS
U
W
0°C ≤ T
A
≤ 70°C, V
S
= ±5V, V
CM
= 0V, V
FS
= 2.5V, I
C
= I
FS
= NULL = Open, Pins 5,10 = GND, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
A
VOL
Large-Signal Voltage Gain V
O
= –3V to 3V, R
L
= 150Ω 83 93 dB
V
O
= –2.75V to 2.75V, R
L
= 150Ω ● 83 dB
R
OL
Transresistance, ∆V
OUT
/∆I
IN
–
V
O
= –3V to 3V, R
L
= 150Ω 0.75 1.8 MΩ
V
O
= –2.75V to 2.75V, R
L
= 150Ω ● 0.75 MΩ
V
OUT
Maximum Output Voltage Swing No Load ● ±4.0 ±4.2 V
R
L
= 150Ω ±3.0 ±3.5 V
● ±2.75 V
V
S
= ±15V, No Load ● ±14.0 ±14.2 V
V
S
= 5V, V
CM
= 2.5V, (Note 6) ● 1.2 3.8 V
I
O
Maximum Output Current V
S
= ±5V ● ±30 ±40 mA
V
S
= 5V, V
CM
= V
O
= 2.5V ● ±20 ±30 mA
I
S
Supply Current V
C
= V
FS
= 2.5V ● 13.5 17.0 mA
V
C
= V
FS
= 1.25V ● 7.5 9.5 mA
V
C
= V
FS
= 0V ● 1.3 1.8 mA
V
C
= V
FS
= 2.5V, V
S
= ±15V ● 14.5 18.5 mA
V
C
= V
FS
= 0V, V
S
= ±15V ● 1.4 2.0 mA
CO TROL A D FULL SCALE A PLIFIER CHARACTERISTICS
UUW
0°C ≤ T
A
≤ 70°C, V
S
= ±5V, V
FS
= 2.5V, I
C
= I
FS
= NULL = Open, Pins 5,10 = GND, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Control Amplifier Input Offset Voltage Pin 4 to Pin 3 ● 515 mV
Full-Scale Amplifier Input Offset Voltage Pin 11 to Pin 12 ● 515 mV
Control Amplifier Input Resistance ● 25 100 MΩ
Full-Scale Amplifier Input Resistance ● 25 100 MΩ
Control Amplifier Input Bias Current ● –750 –300 nA
Full-Scale Amplifier Input Bias Current ● –750 –300 nA
R
C
Internal Control Resistor T
A
= 25°C 3.75 5 6.25 kΩ
R
FS
Internal Full-Scale Resistor T
A
= 25°C 456 kΩ
Resistor Temperature Coefficient 0.2 %/°C
Control Path Bandwidth Small Signal, V
C
= 100mV, (Note 7) 10 MHz
Control Path Rise and Fall Time Small Signal, V
C
= 100mV, (Note 7) 35 ns
Control Path Transition Time 0% to 100% 150 ns
Control Path Propagation Delay Small Signal, ∆V
C
= 100mV 50 ns
V
C
from 0% or 100% 90 ns
The ● denotes specifications which apply over the specified operating
temperature range.
Note 1: A heat sink may be required depending on the power supply
voltage.
Note 2: Commercial grade parts are designed to operate over the
temperature range of –40°C to 85°C but are neither tested nor guaranteed
beyond 0°C to 70°C. Industrial grade parts specified and tested over
–40°C to 85°C are available on special request. Consult factory.
Note 3: T
J
is calculated from the ambient temperature T
A
and the power
dissipation P
D
according to the following formulas:
LT1251CN/LT1256CN: T
J
= T
A
+ (P
D
• 70°C/W)
LT1251CS/LT1256CS: T
J
= T
A
+ (P
D
• 100°C/W)
Note 4: Differential gain and phase are measured using a Tektronix
TSG120YC/NTSC signal generator and a Tektronix 1780R Video
Measurement Set. The resolution of this equipment is 0.1% and 0.1°. Five
identical amplifier stages were cascaded giving an effective resolution of
0.02% and 0.02°.
Note 5: Differential gain and phase are best when the control is set at 0%
or 100%. See the Typical Performance Characteristics curves.
Note 6: Tested with R
L
= 150Ω to 2.5V to simulate an AC coupled load.
Note 7: Small-signal control path response is measured driving R
C
(Pin 5)
to eliminate peaking caused by stray capacitance on Pin 4.