Analog Devices ADM1203 prd Datasheet

© 2005

Preliminary Technical Data

FEATURES

Enables Power Supply Tracking of multiple Supplies
Monitors Current on Supply being Tracked
Up/Down Tracking limits Supply Differences to ~100mV
Capacitor Adjustable Slew Rate
On Board Charge Pump Fully enhances FET
Ability to Track Down Supplies (ADM1203-1/3)
Emergency Shutdown Feature (ADM1203-2/4)
Auto retry after Current Fault (ADM1203-1/2)
Latch off after Current Fault (ADM1203-3/4)
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 ADM1203 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 ADM1203 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 of the
previous device to ensure that supply will track up and down
with the previous supply.

TM

device which

pin of

SLEW

Simple Tracker

TM

with

Circuit Breaker

ADM1203

every cycle determined by the capacitor on the TIMER pin and
the ADM1203-3/4 will latch off the gate until the
up/down(stop) pin is toggled.

The ADM1203 is packaged in a tiny 8-pin TSOT package.

Functional Block Diagram

R

V

IN

UP/DOWN

(ADM1203-1/3)

UP/STOP

(ADM1203-2/4)

C

SLEW

C

TIMER

C

SLEW

C

TIMER

s

V

CC

VCC

SLEWRATE

CONTROL

TIMER

CONTROL

LOGIC

GND

RS-

DRIVER

ADM1203

Applications Diagram

R

C

TIMER

V

cc

UP/DOWN

ADM1203-1

SLEW
TIMER

R

SENSE

SENSE

GND

RS-

GATE

V

OUTFB

5VIN

POWER ON/OFF

3.3VIN

C

SLEW

Q

1

GATE

FET

20nF

V

OUT

V

OUT

Q

1

5VOUT

1nF

Q

1

3.3VOUT

The ADM1203 is offered in four variants. The ADM1203-1/3
features an UP/DOWNb pin and the ADM1203-2/4 features an
Up/STOPb pin. The ADM1203-1/2 features an auto retry on
current RS fault and the ADM1203-3/4 latches off. For all
devices, a high level on the input will initiate tracking power up
sequence. A low on the UP/DOWNb pin of the ADM1203-1/3
will initiate a tracking down of the supply rails, while a low on
the UP/STOPb pin of the ADM1203-2/4 will initiate an
emergency fast shutdown of all supply rails simultaneously.

The ADM1203 features a current sense comparator, which
monitors for an over current condition on the supply. In the
event of an over current condition, a fault is flagged and the gate
is switched off. The ADM1203-1/2 will auto retry this fault at

Rev. PrD

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.

RS-

V

cc

POWER ON/OFF

2.7VIN

POWER ON/OFF

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

C

C

UP/DOWN

SLEW
TIMER

TIMER

UP/DOWN

SLEW
TIMER

TIMER

ADM1203-1

GND

R

SENSE

RS-

V

cc

ADM1203-1

GND

V

V

GATE

OUTFB

GATE

OUTFB

1nF

Q

1

2.7VOUT

1nF

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Preliminary Technical Data

ADM1203—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
RS- Pin
Hot Swap Voltage 2.7 16.5
RS- Pin Input Current, I

Circuit Breaker Limit Voltage, VCB 34 47 60
44 47 53
Over Current Limit Voltage, VOC 40 53 66
50 53 59

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
TIMER Pin
TIMER Pin Pull-Up Current, I

-48 -60 -72
TIMER Pin Pull-Down Current, I
100
TIMER Pin Threshold High, V
TIMER Pin Threshold Low, V

NOTES:

= Full Operating Range, TA = -40°C to +85°C, unless otherwise noted.

CC

2.4 2.525 2.65 V Vcc Rising

UVLO

INRS

5 6.5 10 V V

GATE

-4 -5 -6

TIMERUP

TIMERDN

1.235 1.3 1.365

TIMERH

0.18 0.2 0.22

TIMERL

-100 100 nA

TBD -200 TBD

10 20 30

-10
10

100 1000 V/s

-10 10

2 2.5

V

mA

V

V
µA
µA

mV
mV
mV
mV

µA
µA

µA

µA
µA

mA

µA
µA
µA
µA

V

V

Rising

VRS = VCC, V
VRS = VCC, V
VCB = (V

CC

VCB = (V

CC

V

= 0.6 V

HOTSWAP

V

> 2.2 V

HOTSWAP

HOTSWAP

HOTSWAP

– VRS) ,V
– VRS) ,V

= 0.6 V,
> 2.2 V

HOTSWAP

HOTSWAP

= 0.6 V
> 2.2 V

SLEW/VOUTFB

Vslew – Vout > 100mV
Vout – Vslew > 100mV
ADM1203-2 only –vgate = 3.0V

– VCC; VCC = 2.7V

GATE

– VCC; VCC = 5.0V

GATE

– VCC; VCC = 16.5V

GATE

Initial Cycle, V
During Current Fault, V
After Current Fault, V
Normal Operation, V

TIMER

= 1V

TIMER

TIMER

TIMER

= 1V

= 1V

= 1V

TIMER rising
TIMER falling

Rev. PrD | Page 2 of 8

Preliminary Technical Data ADM1203

Absolute Maximum Ratings

Table 2. ADM1203 Absolute Maximum Ratings

Parameter
VCC Pin 20V
TIMER Pin 20V
UP/DOWNb, UP/STOPb 20V
RS- 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)
Junction Temperature 150°C

Rating

300°C

Rev. PrD | Page 3 of 8