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

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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
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registered trademarks are the property of their respective companies.

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Tel: [phone]
Fax: [phone] © 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