Analog Devices ADM1201 prg 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
Emergency Shutdown Feature
In-Built Power Fail Detector Circuitry
Packaged in tiny 8-Lead TSOT Package

APPLICATIONS

Multi-Voltage Supply Rail Tracker
Telecoms and Datacoms Systems
Multi voltage Network Processors
Multivoltage FPGAs, ASICs, DSPs
PC/Server Applications

GENERAL DESCRIPTION

The ADM1201 is a cascadable Simple Tracker
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.

The Slew Rate of the ramp up and ramp down is adjustable via
an external capacitor on the C

pin and can be programmed

SLEW

from 100V/s to 1000V/s. When multiple devices are cascaded
the C

pin of each subsequent device should be tied to the

SLEW

output rail of the previous device to ensure that supply will
track up and down with the previous supply.

TM

device which

Simple Tracker

with Emergency Shutdown

Functional Block Diagram

V

IN

C

SLEW

Applications Diagram

5VIN

POWER ON/OFF

EMERGENCY

SHUTDOWN

3.3VIN

UP/DOWN

STOP

C

SLEW

2.7V - 16V

UP / DOWN
DETECTOR

V

CC

SLEWRATE

CONTROL

POWER FAIL

DETECTOR

GND

CHARGE

PUMP

LOGIC

ADM1201

ADM1201

V

cc

UP/DOWN
STOP
C

SLEW

DRIVER

GND

TM

ADM1201

Q

1

V

FET

GATE

FET

V

OUTFB

PFI

Q

1

GATE

20nF

V

OUT

PFI

Q2

V

R

1

R

2

5VOUT

R

1

R

2

3.3VOUT

OUT

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..

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.

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.

ADM1201

V

2.8VIN

cc

UP/DOWN
STOP

C

SLEW

GND

GATE

V

OUT

PFI

20nF

Q3

ADM1201

V

cc

UP/DOWN
STOP

C

SLEW

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]

www.analog.com

GND

GATE

V

OUT

PFI

20nF

Fax: [phone]© 2003 Analog Devices, Inc. All rights reserved.

R

3

R

4

2.8VOUT

R

5

R

6

Preliminary Technical Data

ADM1201—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
Stopb Pin
Input Threshold 0.58 0.6 0.62
Input Threshold Hysteresis 60 mV
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

Activated 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
20 mV

-100 100 nA

-10
10

100 1000 V/s

-10 10

V

mA

V

V

µA

µA
µA

µA

µA
µA

mA

Rising

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

Rev. PrG | Page 2 of 6