Datasheet LT1208, LT1209 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | Dual and Quad 45MHz, 400V/µs Op Amps |
| Pages / Page | 12 / 7 — APPLICATI. S I FOR ATIO. Small-Signal Capacitive Loading. Large-Signal … |
| File Format / Size | PDF / 277 Kb |
| Document Language | English |
APPLICATI. S I FOR ATIO. Small-Signal Capacitive Loading. Large-Signal Capacitive Loading. Small-Signal Transient Response
Model Line for this Datasheet
Text Version of Document
LT1208/LT1209
O U U W U APPLICATI S I FOR ATIO Small-Signal Capacitive Loading
caused by a second pole beyond the unity-gain crossover. This is reflected in the 50° phase margin and shows up as overshoot in the unity-gain small-signal transient re- sponse. Higher noise gain configurations exhibit less overshoot as seen in the inverting gain of one response. The large-signal response in both inverting and non- inverting gain show symmetrical slewing characteristics. Normally the noninverting response has a much faster rising edge due to the rapid change in input common- mode voltage which affects the tail current of the input differential pair. Slew enhancement circuitry has been AV = –1 added to the LT1208/LT1209 so that the falling edge slew CL = 1000pF 1208/09 AI01 rate is balanced.
Large-Signal Capacitive Loading Small-Signal Transient Response
AV = 1 CL = 10,000pF 1208/09 AI02 AV = 1 1208/09 AI03
Input Considerations Small-Signal Transient Response
Resistors in series with the inputs are recommended for the LT1208/LT1209 in applications where the differential input voltage exceeds ±6V continuously or on a transient basis. An example would be in noninverting configura- tions with high input slew rates or when driving heavy capacitive loads. The use of balanced source resistance at each input is recommended for applications where DC accuracy must be maximized.
Transient Response
The LT1208/LT1209 gain-bandwidth is 45MHz when mea- sured at 100kHz. The actual frequency response in unity- AV = –1 1208/09 AI04 gain is considerably higher than 45MHz due to peaking 7
O U U W U APPLICATI S I FOR ATIO Small-Signal Capacitive Loading
caused by a second pole beyond the unity-gain crossover. This is reflected in the 50° phase margin and shows up as overshoot in the unity-gain small-signal transient re- sponse. Higher noise gain configurations exhibit less overshoot as seen in the inverting gain of one response. The large-signal response in both inverting and non- inverting gain show symmetrical slewing characteristics. Normally the noninverting response has a much faster rising edge due to the rapid change in input common- mode voltage which affects the tail current of the input differential pair. Slew enhancement circuitry has been AV = –1 added to the LT1208/LT1209 so that the falling edge slew CL = 1000pF 1208/09 AI01 rate is balanced.
Large-Signal Capacitive Loading Small-Signal Transient Response
AV = 1 CL = 10,000pF 1208/09 AI02 AV = 1 1208/09 AI03
Input Considerations Small-Signal Transient Response
Resistors in series with the inputs are recommended for the LT1208/LT1209 in applications where the differential input voltage exceeds ±6V continuously or on a transient basis. An example would be in noninverting configura- tions with high input slew rates or when driving heavy capacitive loads. The use of balanced source resistance at each input is recommended for applications where DC accuracy must be maximized.
Transient Response
The LT1208/LT1209 gain-bandwidth is 45MHz when mea- sured at 100kHz. The actual frequency response in unity- AV = –1 1208/09 AI04 gain is considerably higher than 45MHz due to peaking 7
