Analog Devices ADM1200 prh Datasheet
© 2005
Preliminary Technical Data
FEATURES
Enables Power Supply Tracking of multiple supplies
Up/Down Tracking limits Supply Differences to ~100mV
Capacitor Adjustable Slew Rate
On Board Charge Pump Fully enhances FET
Ability to Track Down Supplies (ADM1200-1)
Emergency Shutdown Feature (ADM1200-2)
Packaged in tiny 6-Lead SOT-23 Package
APPLICATIONS
Multi-Voltage Supply Rail Tracker
Telecoms and Datacom s Systems
Multi voltage Network Processors , FPGAs, ASICs, DSPs
PC/Server Applications
GENERAL DESCRIPTION
The ADM1200 is a cascadable Simple Tracker
ensures that voltage rails track 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 ADM1200 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.
The Slew Rate of the ramp is adjustable via an external capacitor
on the C
pin and can be programmed from 100V/s to
SLEW
1000V/s. When multiple devices are cascaded the C
each subsequent device should be tied to the output rail(V
of the previous device to ensure that supply will track up and
down with the previous supply.
The ADM1200 is offered in two variants. The ADM1200-1
features an UP/DOWNb pin and the ADM1200-2 features an
Up/STOPb pin. For both devices a high level on the this input
will initiate tracking power up sequence. A low on the
UP/DOWNb pin of the ADM1200-1 will initiate a tracking
down of the supply rails, while a low on the UP/STOPb pin of
the ADM1200-2 will initiate an emergency fast shutdown of all
supply rails simultaneously.
The ADM1200 is packaged in a tiny 6-pin SOT-23 package.
TM
device which
pin of
SLEW
OUTFB
)
Simple Tracker
Functional Block Diagram
V
IN
2.7V - 16.5V
V
CC
V
CHARGE
UP/DOWN
(ADM1200-1)
UP/STOP
(ADM1200-2)
C
SLEW
C
SLEW
UP / DOWN
DETECTOR
SLEW RATE
CONTROL
LOGIC
GND
Applications Diagram
3.3VIN
UP/DOWN
2.5VIN
1.5VIN
V
cc
ADM1200
V
cc
UP/DOWN
C
SLEW
V
cc
V
cc
UP/DOWN
C
SLEW
V
cc
V
cc
UP/DOWN
C
SLEW
GND
ADM1200
GND
ADM1200
GND
C
SLEW
PUMP
FET
DRIVER
ADM1200
GATE
V
OUT
GATE
V
OUT
GATE
V
OUT
FET
20nF
20nF
20nF
ADM1200
Q
1
GATE
V
OUT
Q
1
3.3VOUT
Q
2
2.5VOUT
Q
3
1.5VOUT
V
TM
OUT
Rev. PrH
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 Anal og 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 © 2003 Analog Devices, Inc. All rights reserved.
www.analog.com
Preliminary Technical Data
ADM1200—SPECIFICATIONS
Table 1. V
Parameter Min Typ Max Units Conditions
VCC Pin
Operating Voltage Range Vcc 2.7 16.5 V
Undervoltage Lockout, V
UVLO Hysteresis 25 mV
Switched Voltage Range 0.65 16.5
Quiesent Current 0.65 1.0
Up/Downb Pin
Input Threshold 0.58 0.6 0.62
Input Threshold Hysteresis 60 mV
Input Current
C
Pin
SLEW
Slew up Current
Slew down Current
Tracking Gain 1 V/V V
Minimum Tracking Voltage 0.1 V
Maximum Tracking voltage Vcc – 0.3 V
Slew Rate
V
Pin
OUTFB
Input Current
Voltage Range 0 Vcc V
GATE Pin
Gate Pullup Current 12
Gate Pulldown Current 12
Gate Pulldown Current 2
GATE Voltage, V
6 8 12 V V
5 6.5 10 V V
NOTES:
1
Asserted when voltage on PFI pin exceeds threshold
= Full Operating Range, TA = -40°C to +85°C, unless otherwise noted.
CC
2.4 2.525 2.65 V Vcc Rising
UVLO
5 6.5 10 V V
GATE
-100 100 nA
-10
10
100 1000 V/s
-10 10
V
mA
V
µA
µA
µA
µA
µA
mA
Rising
SLEW/VOUTFB
Vslew – Vout > 100mV
Vout – Vslew > 100mV
ADM1200-2 only –vgate = 3.0V
– VCC; VCC = 2.7V
GATE
– VCC; VCC = 5.0V
GATE
– VCC; VCC = 16.5V
GATE
Absolute Maximum Ratings
Table 2. ADM1200 Absolute Maximum Ratings
Parameter
VCC Pin 20V
UP/DOWNb, UP/STOPb 20V
C
Pin 20V
SLEW
Gate Pin Vcc + 11V
V
Pin 20V
OUTFB
Power Dissipation TBD
Storage Temperature –65°C to +125°C
Operating Temperature Range –40°C to +85°C
Lead Temperature Range
(Soldering 10 sec)
Junction Temperature 150°C
Rating
300°C
Rev. PrH | Page 2 of 6
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