LT1222C Linear Technology, LT1222C Datasheet - Page 6

• Manufacturer Part Number: LT1222C
• Description: 500MHz Operational Amplifier
• Manufacturer: Linear Technology

APPLICATIONS
LT1222
TYPICAL PERFORMANCE CHARACTERISTICS
The LT1222 is stable in noise gains of 10 or greater and
may be inserted directly into HA2520/2/5, HA2541/2/4,
AD817, AD847, EL2020, EL2044 and LM6361 applica-
tions, provided that the nulling circuitry is removed and
the amplifier configuration has a high enough noise gain.
The suggested nulling circuit for the LT1222 is shown in
the following figure.
6
Small Signal, A
R
R
Small Signal, A
R
R
F
G
F
G
= 1k
= 909
= 100 (75)
= 100
V
V
S
IN
= 15V
= 20mV
V
V
S
IN
= 15V
= 20mV
V
V
3
2
= 10
= – 10
f = 5MHz
U
+
–
f = 5MHz
LT1222
1
5k
Offset Nulling
INFORMATION
8
U
W
LT1222 • TPC19
LT1222 • TPC22
V
V
+
–
7
4
6
U
W
0.1 F
0.1 F
LT1222 • AI01
Large Signal, A
R
R
Large Signal, A
R
R
F
G
F
G
= 909
= 1k
= 100
= 100 (75)
U
V
V
S
IN
= 15V
= 2V
V
V
S
IN
= 15V
= 2V
V
V
= 10
= – 10
f = 2MHz
Layout and Passive Components
The LT1222 amplifier is easy to apply and tolerant of less
than ideal layouts. For maximum performance (for ex-
ample, fast settling time) use a ground plane, short lead
lengths and RF-quality bypass capacitors (0.01 F to 0.1 F).
For high drive current applications use low ESR bypass
capacitors (1 F to 10 F tantalum). Sockets should be
avoided when maximum frequency performance is re-
quired. For more details see Design Note 50. Feedback
resistors greater than 5k are not recommended because a
pole is formed with the input capacitance which can cause
peaking or oscillations. Stray capacitance on pin 5 should
be minimized. Bias current cancellation circuitry is em-
ployed on the inputs of the LT1222 so the input bias current
and input offset current have identical specifications. For
this reason, matching the impedance on the inputs to
reduce bias current errors is not necessary.
f = 2MHz
LT1222 • TPC20
LT1222 • TPC23
R
R
Large Signal, A
C
R
R
Small Signal, A
C
F
G
F
G
L
L
= 1k
= 909
= 100
= 100 (75)
= 10,000pF
= 1,000pF
V
V
S
IN
= 15V
V
V
= 2V
S
IN
= 15V
= 15mV
V
V
= 10,
= – 10,
f = 20kHz
f = 500kHz
LT1222 • TPC21
LT1222 • TPC24