TM
Simple Tracker
with Emergency Shutdown
Preliminary Technical Data
ADM1201
FEATURES
Functional Block Diagram
Enables Power Supply Tracking of multiple supplies
Up/Down Tracking limits Supply Differences to ~100mV
Capacitor Adjustable Slew Rate
Q
1
V
V
IN
OUT
2.7V - 16V
On Board Charge Pump Fully enhances FET
Emergency Shutdown Feature
V
CC
V
CHARGE
PUMP
FET
In-Built Power Fail Detector Circuitry
Packaged in tiny 8-Lead TSOT Package
UP/DOWN
STOP
GATE
FET
DRIVER
UP
DETECTOR
/ DOWN
LOGIC
APPLICATIONS
Multi-Voltage Supply Rail Tracker
Telecoms and Datacoms Systems
Multi voltage Network Processors
Multivoltage FPGAs, ASICs, DSPs
PC/Server Applications
C
SLEW
SLEW RATE
CONTROL
V
OUTFB
R
1
PFI
POWER FAIL
DETECTOR
C
SLEW
ADM1201
R
2
GND
GENERAL DESCRIPTION
The ADM1201 is a cascadable Simple Tracker TM device which
ensures that voltage rails track up and ramp within ~100mV of
each other in multi supply systems. Any number of these
devices can be cascaded to form a multi supply tracking
solution. The ADM1201 requires 2.7V to 16.5V on its Vcc pin
to operate. An on-board charge pump generates a high voltage
GATE drive to fully enhance FETs in the power path.
Applications Diagram
Q
1
5VIN
5VOUT
ADM1201
V
cc
GATE
20nF
POWER ON/OFF
UP/DOWN
STOP
R
1
V
OUT
PFI
The Slew Rate of the ramp up and ramp down is adjustable via
an external capacitor on the CSLEW pin and can be programmed
from 100V/s to 1000V/s. When multiple devices are cascaded
the CSLEW pin of each subsequent device should be tied to the
output rail of the previous device to ensure that supply will
track up and down with the previous supply.
EMERGENCY
SHUTDOWN
C
SLEW
R
GND
2
Q2
3.3VIN
3.3VOUT
ADM1201
The ADM1201 features an Up/Downb pin for external control
of the Up and Down tracking. A low-to-high transition on the
this input will initiate tracking power up sequence., while a
high-to-low will initiate a tracking down of the supply rails. A
STOPb pin is also available- a high-to-low on this pin will
initiate an emergency fast shutdown of the supply..
V
cc
GATE
20nF
UP/DOWN
STOP
R
V
3
OUT
PFI
C
SLEW
GND
R
4
Q3
Power Fail Detector circuitry is also present. A resistor divider
on the PFI input will dictate what level the ADM1201 registers a
power fail on that supply. When a power fail is detected the
internal Power Fail Comparator will pull the STOPb pin down
which will shut down the output immediately. STOPb pins of
multiple ADM1201 devices may be tied together so that a fault
on any supply rail will cause all devices to go into emergency
shutdown.
2.8VIN
2.8VOUT
ADM1201
V
cc
GATE
20nF
UP/DOWN
STOP
R
5
V
OUT
PFI
C
SLEW
GND
R
6
The ADM1201 is available in a tiny 8-pin TSOT package.
Rev. PrG
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its
use. Specifications subject to change without notice. No license is granted by
implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective
companies.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.326.8703
www.analog.com
© 2003 Analog Devices, Inc. All rights reserved.
2005