Analog Devices ADM1172 pre Datasheet

© 2005

2.7V to 16.5V Hot Swap Controller

Preliminary Technical Data

FEATURES

Allows Safe Board Insertion and Removal from a Live
Backplane

Controls Supply Voltages from 2.7 V to 16.5V
Power Good Comparator
Adjustable Analog Current Limit with Circuit Breaker
Fast Response Limits Peak Fault Current
Automatic Retry or Latch-Off On Current Fault
Adjustable Supply Voltage Power-Up Rate
Charge Pumped Gate Drive for External N-FET Switch
TIMER pin allows control over timing functions
Undervoltage Lockout
Adjustable Overvoltage Protection
8-pin TSOT Package

APPLICATIONS

Hot Swap Board Insertion – Line Cards, Raid systems
Electronic Circuit Breaker
Industrial High Side Switch/Circuit Breaker

APPLICATIONS DIAGRAM

VIN=5V

LONG

with Power-Good Comparator

ADM1172

GENERAL DESCRIPTION

The ADM1172 is a Hot Swap controller that allows a board to
be safely inserted and removed from a live backplane.
An internal charge pumped driver controls the GATE of an
external high side N-channel FET for a supply voltage ranging
from 2.7V to 16.5V. The ADM1172 provides the initial timing
cycle and allows the GATE to be ramped up at an adjustable
rate.
The ADM1172 features a fast current limit loop providing
active current limiting together with a circuit breaker timer.
The signal at the ON pin turns the part on and off and is also
used for the reset function.
Voltages can be monitored using an integrated comparator for
power good/fail conditions.
A capacitor connected to the TIMER pin gives the user control
over the duty cycle of the PWM retry ratio during current fault.
This part is available in two options: the ADM1172-1 will
automatic retry for over-current fault and the ADM1172-2 will
latch-off for an over-current fault.
The ADM1172 is packaged in an 8-lead TSOT package.

R

SENSE

Q

1

V

OUT

=5V

R

ON1

R

ON2

C

TIMER

ON

TIMER

GND

SHORT

LONG

Rev.PrE

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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
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cc

SENSE-

V

ADM1172

GND

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

GATE

PFI

PFO

C

LOAD

R

PFI1

R

PFI2

GND

www.analog.com

Preliminary Technical Data ADM1172

SPECIFICATIONS

Table 1. V

Parameter Min Typ Max Units Conditions

VCC Pin

Operating Voltage Range, VCC 2.7 16.5 V
Supply Current, Icc 0.65 1.0
Undervoltage Lockout, V
Undervoltage Lockout Hysteresis, V

ON Pin
ON Pin Input Current, I
On Pin Threshold, VON 1.26 1.3 1.34
ON Pin Threshold Hysteresis, V
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
GATE Pin
GATE Drive Voltage, V
GATE Drive Voltage, V
GATE Drive Voltage, V

Gate Pullup Current
Gate Pulldown Current
Gate Pulldown Current
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

PFI Pin

Threshold Rising 0.58 0.6 0.62 V
Threshold Hysteresis 20
Input Current -100 0 100

PFO Pin

Pullup Current -10
Output Low Voltage 0.4
Output Low Current 200

= 2.7V to 16.5V, TA = -40°C to +85°C, Typical Values at TA = 25°C unless otherwise noted.

CC

ON rising

V
V
VCB = (V
VCB = (V
V
V

mA

2.4 2.525 2.65 V VCC Rising

UVLO

25

UVLOHYS

mV

INON

-100 0 100

nA

V

80

ONHYST

mV

V

INSENSE

TBD -200 TBD

10 20 30

µA

µA
mV
mV
mV
mV

GATE

6 8 12 V V

GATE

5 6.5 10 V V

GATE

5 6.5 10 V V

10 12 14 uA V

2 mA V
25 mA V

-4 -5 -6

TIMERUP

µA

µA

TIMERDN

2 2.5

µA

µA

1.235 1.3 1.365

TIMERH

0.18 0.2 0.22

TIMERL

V
V

Initial Cycle, V
During Current Fault, V
After Current Fault, V
Normal Operation, V
TIMER rising
TIMER falling

mV

nA

µA

V

µA

= VCC, V

SENSE

SENSE

HOTSWAP

HOTSWAP

– VCC, VCC = 2.7V

GATE

– VCC, VCC = 5V

GATE

– VCC, VCC = 16.5V

GATE

= 0V

GATE

= 3V, Vcc > UVLO

GATE

= 3V, Vcc < UVLO

GATE

HOTSWAP

= VCC, V

HOTSWAP

– V

CC

SENSE

– V

CC

SENSE

= 0.6 V, Note
> 2.2 V

= 0.6 V, Note
> 2.2 V

) ,V

HOTSWAP

) ,V

HOTSWAP

= 1V

TIMER

TIMER

TIMER

TIMER

= 1V

= 1V

= 0.6 V
> 2.2 V

= 1V

Rev. PrE | Page 2 of 8

Preliminary Technical Data ADM1172

Absolute Maximum Ratings

Parameter
VCC Pin 20V
RS+, RS- Pins -0.3V to 20V
TIMER Pin -0.3V to (VCC + 0.3V)
SS Pin TBD
ON Pin -0.3V to 20V
GATE Pin VCC + 11V
Power Dissipation TBD
Storage Temperature –65°C to +125°C
Operating Temperature Range –40°C to +85°C
Lead Temperature Range (10 sec) 300°C
Junction Temperature 150°C

Rating

Rev. PrE | Page 3 of 8