Datasheet LT1221 (Analog Devices) - 6

LT1221
W U TYPICAL PERFORMANCE CHARACTERISTICS Large Signal, AV = 4, Small Signal, A Large Signal, A V = 4 V = 4 CL = 10,000pF
V LT1221 • TPC21 S = ±15V f = 5MHz LT1221 • TPC19 VS = ±15V f = 2MHz LT1221 • TPC20 V f = 20kHz S = ±15V VIN = 25mV VIN = 5VP-P VIN = 5VP-P
Small Signal, AV = – 4, Small Signal, AV = – 4 Large Signal, AV = – 4 CL = 1,000pF
VS = ±15V f = 5MHz LT1221 • TPC22 VS = ±15V f = 2MHz LT1221 • TPC23 LT1221 • TPC24 V f = 500kHz S = ±15V VIN = 25mV VIN = 5VP-P VIN = 42mV
U U W U APPLICATIONS INFORMATION
The LT1221 is stable in noise gains of 4 or greater and may
Layout and Passive Components
be inserted directly into HA2520/2/5, HA2541/2/4, AD817, The LT1221 amplifier is easy to apply and tolerant of less AD847, EL2020, EL2044 and LM6361 applications, pro- than ideal layouts. For maximum performance (for ex- vided that the nulling circuitry is removed and the ampli- ample, fast settling time) use a ground plane, short lead fier configuration has a high enough noise gain. The lengths and RF-quality bypass capacitors (0.01µF to 0.1µF). suggested nulling circuit for the LT1221 is shown in the For high drive current applications use low ESR bypass following figure. capacitors (1µF to 10µF tantalum). Sockets should be avoided when maximum frequency performance is re-
Offset Nulling
quired, although low profile sockets can provide reason- V+ able performance up to 50MHz. For more details see Design Note 50. Feedback resistors greater than 5k are not 5k 1 0.1µF recommended because a pole is formed with the input 3 8 + 7 capacitance which can cause peaking or oscillations. 6 LT1221 2 4 –
Input Considerations
0.1µF Bias current cancellation circuitry is employed on the V– LT1221 • AI01 inputs of the LT1221 so the input bias current and input 6