LF442MH National Semiconductor, LF442MH Datasheet - Page 8

• Manufacturer Part Number: LF442MH
• Description: Dual Low Power JFET Input Operational Amplifier
• Manufacturer: National Semiconductor

www.national.com
Typical Applications
R
Trim 5k for 10 µA through the 5k–120k combination
*1% film resistor
• T
• A1’s output represents the amplified difference between the LM335 temperature sensor and the crystal oven’s temperature
• A2, a free running duty cycle modulator, drives the LM395 to complete a servo loop
• Switched mode operation yields high efficiency
• 1% metal film resistor
T
= Tel Labs type Q81
control
= 75˚C
(Continued)
High Efficiency Crystal Oven Controller
Conventional Log Amplifier
8
DS009155-13
DS009155-14