Analog Devices ADM1202 prf 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 (ADM1202-1)
Emergency Shutdown Feature (ADM1202-2)
In-Built Power Good Detector Circuitry
Packaged in tiny 8-Lead TSOT 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 ADM1202 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 ADM1202 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 ADM1202 is offered in two variants. The ADM1202-1
features an UP/DOWNb pin and the ADM1202-2 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 ADM1202-1 will initiate a tracking
down of the supply rails, while a low on the UP/STOPb pin of
the ADM1202-2 will initiate an emergency fast shutdown of all
supply rails simultaneously.
Power Fail Detector circuitry is also present. A resistor divider
on the PFI input will dictate what level the ADM1202 registers a
power fail on that supply. When a power fail is detected the
Power Fail Output (PFO) will assert.
The ADM1202 is packaged in a tiny 8-pin TSOT package.
TM
device which
pin of
SLEW
OUTFB
)
Simple Tracker
with Power-Good Comparator
ADM1202
Functional Block Diagram
Q
GATE
1nF
V
OUTFB
PFI
5VOUT
R
1
R
2
3.3VOUT
R
3
R
4
2.8VOUT
R
5
R
6
1
5V POWER GOOD
3.3V POWER GOOD
2.8V POWER GOOD
R
1
R
2
V
IN
UP/DOWN
UP/STOP
POWER ON/OFF
(ADM1202-1)
(ADM1202-2)
C
SLEW
5VIN
3.3VIN
2.8VIN
2.7V - 16V
V
CC
V
CHARGE
FET
PUMP
UP / D OWN
DETECTOR
C
SLEW
PFO
SLEW RATE
CONTROL
POWER FAIL
DETECTOR
GND
LOGIC
ADM1202
FET
DRIVER
Applications Diagram
Q
1
VCC
ADM1202-1
GND
ADM1202-1
GND
ADM1202-1
GND
PFO
GATE
V
PFO
GATE
V
PFO
GATE
V
1nF
OUT
PFI
Q2
1nF
OUT
PFI
Q3
1nF
OUT
PFI
V
cc
UP/DOWN
C
SLEW
VCC
VCC
SLEW
V
cc
UP/DOWN
C
SLEW
V
cc
UP/DOWN
C
SLEW
C
TM
V
OUT
Rev. PrF
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 © 2004 Analog Devices, Inc. All rights reserved.
www.analog.com
Preliminary Technical Data
ADM1202—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
Power Fail Output, PFO Pin
Internal Pull Up -5
Output Low Voltage 0.4 V Note 1, Iload = 300uA
Power Fail Detector, PFI Pin
PFI Detector Threshold
PFI Detector Hysterisis
PFI 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
0.58 0.6 0.62 V
10 mV
-100 100 nA
-10
10
100 1000 V/s
-10 10
V
mA
V
µA
µA
µA
µA
µA
µA
mA
Rising
SLEW/VOUTFB
Vslew – Vout > 100mV
Vout – Vslew > 100mV
ADM1202-2 only –vgate = 3.0V
– VCC; VCC = 2.7V
GATE
– VCC; VCC = 5.0V
GATE
– VCC; VCC = 16.5V
GATE
Absolute Maximum Ratings
Table 2. ADM1202 Absolute Maximum Ratings
Parameter
VCC Pin 20V
PFI Pin 20V
UP/DOWNb, UP/STOPb 20V
PFO Pin 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)
Rating
300°C
Junction Temperature 150°C
Rev. PrF | Page 2 of 6
Loading...