SMT4504
Four-Channel Loss-Less Trakker
TM
Power Supply Manager
FEATURES & APPLICATIONS
•
Loss-Less Tracking function
-
No power MOSFET switches
•
Programmable Slew-Rate, Tracking and Voltage
Monitoring Functions
•
Directly Interfaces to DC-DC Converters,
Monolithic Controllers or LDOs
•
Programmable Sequence Orders
•
Programmable Tracking Slew Rates
•
Eliminates Series Power MOSFETs
•
Programmable OV/UV Threshold Limits
•
Under Voltage Lock-Out (VDD and VCTRL_SUP)
•
4k-Bit user configurable Nonvolatile Memory
•
I
2
C 2-wire serial bus for programming
configuration and monitoring status
Preliminary Information
1
(See Last Page)
INTRODUCTION
The SMT4504 is an intelligent power supply
sequencer, tracker, and voltage monitor. The
SMT4504 tracks or sequences up to 4 power supplies
by uniquely controlling the Enable and TRIM (Soft-
Start) functions of DC-DC converters, Monolithic
Controllers or LDOs. Each Channel is individually
programmable for undervoltage/overvoltage threshold
settings, sequence position and slew rates. Two or
more supplies allocated to the same sequence
position are tracked, while assigning individual
supplies to a unique sequence position causes them
to be sequenced with controlled slew rates.
The SMT4504 monitors the supplies for faults and
is programmable to take any of several actions upon
the occurrence of a fault. The voltage monitoring
threshold step size is better than
±1%.
Power supply sequencing can be executed in any
order. During power-off sequencing, the SMT4504
sequences the supplies in the reverse order as power-
on.
Using the I
2
C interface, a host system can
communicate with the SMT4504 status register,
optionally control power-on/off software and utilize 4K-
bits of nonvolatile memory.
Applications
•
Monitor, Sequence and Slew-Rate Control of
Distributed Power and Point of Use Power
Supplies
•
Multi-voltage Processors, DSPs, ASICs used in
Telecom, CompactPCI or server systems
SIMPLIFIED APPLICATIONS DRAWING
5V
12V
VCTRL_SUP
GND
VDD
5V
DC-DC
Converter
VIN
V+
TRIM
ON/OFF
V-
2.5VIN
GND
DSP/
µP/
NPU/
FPGA/
ASIC
VDD_CAP
VCTRL
A
PUP
A
I2C
BUS
SDA
SCL
SMT4504
VM
A
Monolithic
Controller
VIN
VCTRL
B
PWR_ON
PWR_ON#
PUP
B
-E/A
Soft-Start
V+
V-
1.2VIN
GND
IRQ#
VM
B
IRQ#
Figure 1 – Applications Schematic, the SMT4504 Loss-Less Trakker
TM
can track different types of supplies
together.
Note: This is an applications example only. Some pins, components and values are not shown.
Summit Microelectronics, Inc
2071 1.1 01/07/05
1
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
