The LM78S40 is a monolithic regulator subsystem consisting of all the active building blocks necessary for switching regulator systems. The device consists of a temperature compensated voltage reference, a duty-cycle controllable oscillator with an active current limit circuit, an error amplifier, high current, high voltage output switch, a power diode and an uncommitted operational amplifier. The device can drive external NPN or PNP transistors when currents in excess of 1.5A or voltages in excess of 40V are required. The device can be used for step-down, step-up or inverting switching regulators as well as for series pass regulators. It features wide supply voltage range, low standby power dissipation, high efficiency and low drift. It is useful for any stand-alone, low part count switching system and works extremely well in battery operated systems.

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• Step-up, step-down or inverting switching regulators
• Output adjustable from 1.25V to 40V
• Peak currents to 1.5A without external transistors
• Operation from 2.5V to 40V input
• Low standby current drain
• 80 dB line and load regulation
• High gain, high current, independent op amp
• Pulse width modulation with no double pulsing

• Vin (Min) (V)
• 2.5
• Vin (Max) (V)
• 40
• Vout (Min) (V)
• 1.245
• Vout (Max) (V)
• 40
• Regulated outputs (#)
• 1
• Switching frequency (Min) (kHz)
• 0.1
• Switching frequency (Max) (kHz)
• 100
• Iq (Typ) (mA)
• 1.8
• Features
• Adjustable Current Limit, Nonsynchronous
• Rating
• Catalog

LM78S40的完整型号有：LM78S40CN/NOPB，以下是这些产品的关键参数及官网采购报价：

LM78S40CN/NOPB，工作温度：0 to 70，封装：PDIP (NFG)-16，包装数量MPQ：25个，MSL 等级/回流焊峰值温度：Level-1-NA-UNLIM，引脚镀层/焊球材料：SN，TI官网LM78S40CN/NOPB的批量USD价格：.751（1000+）

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