LTC1157 - 3.3V Dual Micropower High-Side/Low-Side MOSFET Driver
Datasheet 
DocumentationDatasheet
Application Note
- AN51 - Power Conditioning for Notebook and Palmtop Systems
- AN53 - Micropower High Side MOSFET Drivers
- AN66 - Linear Technology Magazine Circuit Collection, Volume II
Design Note
- DN71 - Regulator Circuit Generates Both 3.3V and 5V Outputs from 3.3V or 5V to Run Computers and RS232
- DN76 - PC Card Power Management Techniques
Reliability Data
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Features
- Allows Lowest Drop 3.3V Supply Switching
- Operates on 3.3V or 5V Nominal Supplies
- 3 Microamps Standby Current
- 80 Microamps ON Current
- Drives Low Cost N-Channel Power MOSFETs
- No External Charge Pump Components
- Controlled Switching ON and OFF Times
- Compatible with 3.3V and 5V Logic Families
- Available in 8-Pin SOIC
Typical Application
Description
The LTC1157 dual 3.3V micropower MOSFET gate driver makes it possible to switch either supply or ground reference loads through a low R DS(ON) Nchannel switch (N-channel switches are required at 3.3V because P-channel MOSFETS do not have guaranteed R DS(ON) with VGS </= 3.3V). The LTC1157 internal charge pump boosts the gate drive voltage 5.4V above the positive rail (8.7V above ground), fully enhancing a logic level N-channel switch for 3.3V high-side applications and a standard N-channel switch for 3.3V low-side applications. The gate drive voltage at 5V is typically 8.8V above supply (13.8V above ground), so standard N-channel MOSFET switches can be used for both high-side and low-side applications. Micropower operation, with 3µA standby current and 80µA operating current, makes the LTC1157 well suited for battery-powered applications. The LTC1157 is available in both 8-pin DIP and SOIC.N-8,SO-8
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC1157CN8#PBF | PDIP | 8 | C | $3.00 | $2.45 |
| LTC1157CS8#PBF | SO | 8 | C | $3.15 | $2.55 |
| LTC1157CS8#TRPBF | SO | 8 | C | $2.61 | |
| LTC1157CN8 | PDIP | 8 | C | $6.00 | $4.90 |
| LTC1157CS8 | SO | 8 | C | $6.30 | $5.10 |
| LTC1157CS8#TR | SO | 8 | C | $5.22 |
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.