LTC2926_15 Datasheet, PDF (1/28 Pages) Linear Technology – MOSFET-Controlled Power Supply Tracker

LTC2926
MOSFET-Controlled
Power Supply Tracker
FEATURES
■ _{Flexible Power Supply Tracking and Sequencing}
■ _{Adjustable Ramp Rates, Offsets and Time Delays}
■ _{Controls Three Supplies with Series MOSFETs}
■ _{Integrated Remote Sense Switching}
■ _{FAULT Input/Output}
■ _{STATUS Output/Power Good Input}
■ _{Available in 20-Lead Narrow SSOP and 20-Lead QFN}
(4mm × 5mm) Packages
U
APPLICATIO S
■ _{VCORE and VI/O Supply Tracking}
■ _{Microprocessor, DSP and FPGA Supplies}
■ _Servers
■ _{Communications Systems}
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Protected by U.S. Patents including 6897717.
DESCRIPTIO
The LTC2926 provides a simple solution for tracking and
sequencing up to three power supply rails. An N-channel
MOSFET and a few resistors per channel configure the
load voltages to ramp up and down together, with voltage
offsets, with time delays or with different ramp rates.
Automatic remote sense switching compensates for voltage
drops across the MOSFETs. The LTC2926 provides two
integrated switches as well as a signal to control optional
additional external N-channel MOSFET sense switches.
The LTC2926 includes I/O signals for communication with
other devices. The status output asserts after tracking and
sequencing have completed. A low voltage on the power
good input after an adjustable timeout period causes load
disconnect. A low voltage on the fault I/O causes immedi-
ate load disconnect. Until it is reset, a fault latch prevents
tracking and keeps the loads disconnected.
TYPICAL APPLICATIO
1.8V MODULE
OUT
SENSE
100Ω
IRF7413Z
10Ω
1.8V
SLAVE1
3.3V MODULE
OUT
SENSE
100Ω
0.1µF
IRF7413Z
10Ω
3.3V
SLAVE2
15.0k
15.0k
9.53k
4.02k
V_CC
10k
FAULT
ON/OFF
V_CC SGATE2 SGATE1
D1
S1
D2
FB1
RAMPBUF
15.0k
9.53k
S2
TRACK1
LTC2926
FB2
TRACK2
FAULT
ON
STATUS/PGI
MGATE
GND
PGTMR ^RAMP
2926 TA01
1µF
15.0k
V_CC
4.02k
10k
STATUS
0.1µF
500mV/DIV
3.3V SLAVE2
1.8V SLAVE1
3.3V SLAVE2
1.8V SLAVE1
5ms/DIV
2926 TA01b
500mV/DIV
5ms/DIV
2926 TA01c
2926fa
1