Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - hot swap controller -48 V SOIC 16 Surface-mount

General Description

The MAX5911/MAX5912 are fully integrated hot-swap

switches for negative supply rails. These devices allow

the safe insertion and removal of circuit cards into live

backplanes or ports without causing problematic glitch-

es on the negative power-supply rail. They also monitor

various circuit parameters and disconnect the load if a

fault condition occurs, alerting the host with a logic-level

FAULT output. The MAX5911/MAX5912 operate over a

voltage range of -16V to -65V and are designed to permit

hot plugging of an IP phone into a hub, but are not limit-

ed to that operation.

During startup, an internal power FET regulates the cur-

rent between the backplane power source and the load

to 280mA for MAX5911 and 415mA for MAX5912. After

startup, the FET is fully enhanced to reduce its on-resis-

tance. To ensure robust operation, the MAX5911/

MAX5912 contain built-in safety features that prevent

damage to the internal FET. They include an enable

input, which responds to positive logic signals (+3.3V or

+5V), allowing the host system to disconnect the load.

ENABLE is also used to reset the device after a latching

fault condition occurs.

The MAX5911/MAX5912 Simple Swapper™ hot-swap

ICs monitor four parameters for these fault conditions:

undervoltage lockout (UVLO), power-not-good, zero-

current detection, and thermal shutdown. These

devices are available in the extended temperature

range, -40°C to +85°C. The MAX5911 and MAX5912

come in 8-pin and 16-pin SOIC packages, respectively.

Applications

Features

♦ Provides Safe Hot Swap for -16V to -65V Power

Supplies

♦ 280mA Current Limit for MAX5911

♦ 415mA Current Limit for MAX5912

♦ Zero-Current Load Disconnect

♦ Integrated Power FET

♦ Status Output Reports Fault Condition

♦ Internal Switch-Protection Circuitry

♦ Built-In Thermal Shutdown

♦ DGND Can Vary Up to ±5V with Respect to AGND

MAX5911/MAX5912

-48V Simple Swapper Hot-Swap Switches

________________________________________________________________ Maxim Integrated Products 1

AGND

ENABLEDGND

UVLO

OUT

FAULT

GATE

8 SO

TOP VIEW

MAX5911

OUT

N.C.*

UVLO

N.C.*

16 SO

MAX5912

ENABLE

N.C.*

AGND

GATE

N.C.*

DGND

FAULT

*THESE PINS ARE NOT INTERNALLY CONNECTED.

Pin Configurations

FAULT

ENABLE

DGND

UVLO

AGND

POSITIVE

LOGIC

0.1µF

3.3kΩ

+3.3V

OUT

LOAD

(-48V)

MAX5911

MAX5912

AGND

DGND

Typical Operating Circuit

19-1832; Rev 0a; 1/01

For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

Simple Swapper is a trademark of Maxim Integrated Products, Inc.

PART TEMP. RANGE PIN-PACKAGE

MAX5911ESA -40°C to +85°C 8 SO

MAX5912ESE -40°C to +85°C 16 SO

IP Phones

Network Routers

Network Switches

Internet Appliances

Power-Over-LAN

Summary of content (8 pages)

PAGE 1
9-1832; Rev 0a; 1/01 -48V Simple Swapper Hot-Swap Switches Features ♦ Provides Safe Hot Swap for -16V to -65V Power Supplies ♦ 280mA Current Limit for MAX5911 ♦ 415mA Current Limit for MAX5912 ♦ Zero-Current Load Disconnect ♦ Integrated Power FET ♦ Status Output Reports Fault Condition ♦ Internal Switch-Protection Circuitry ♦ Built-In Thermal Shutdown ♦ DGND Can Vary Up to ±5V with Respect to AGND Ordering Information PART TEMP.
PAGE 2
MAX5911/MAX5912 -48V Simple Swapper Hot-Swap Switches ABSOLUTE MAXIMUM RATINGS Voltages are with respect to AGND, unless otherwise noted. VIN ..........................................................................+0.3V to -70V VOUT ............................................................+0.3V to (VIN - 0.3V) ENABLE to DGND ..................................................-0.3V to +11V ENABLE to VIN .......................................................-0.3V to +70V FAULT to DGND ..................
PAGE 3
-48V Simple Swapper Hot-Swap Switches (VIN = -48V, AGND = DGND = 0, UVLO = open circuit, VENABLE = +3.3V, and TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
Typical Operating Characteristics (continued) (VIN = -48V, AGND = DGND = 0, UVLO = open circuit, VENABLE = +3.3V, RLOAD = 1.8kΩ, TA = +25°C, unless otherwise noted.) MAX5911 TURN-ON WAVEFORMS (RL = 1.8kΩ, CL = 47µF) MAX5911 TURN-OFF WAVEFORMS (RL = 1.
PAGE 5
-48V Simple Swapper Hot-Swap Switches MAX5912 TURN-OFF WAVEFORMS (RL = 1.
PAGE 6
MAX5911/MAX5912 -48V Simple Swapper Hot-Swap Switches MAX5911/MAX5912 FAULT LEVEL SHIFTER ENABLE Normal Operation CONTROL LOGIC AGND include an enable input that responds to positive logic, allowing the host system to turn the FET switch on or off. The enable input is also used to reset the devices after an error condition has latched the output FET off. DGND 2.11MΩ GATE UVLO 99.5kΩ +1.258VREF VIN VOUT |VIN| VPG (min) = 1.
PAGE 7
-48V Simple Swapper Hot-Swap Switches VIN (-16V TO -65V) VOUT VIN 0.1µF R1 +3.3V UVLO R2 3.3kΩ MAX5911 MAX5912 LOAD FAULT POSITIVE LOGIC Changing the Undervoltage Lockout Setting The UVLO value defaults to -28V if the UVLO pin is left open circuit. The lockout voltage can be changed with a resistive divider. Connect the divider from V IN to AGND, and connect the center node of the divider to the UVLO pin. Figure 2 shows an example circuit.
PAGE 8
-48V Simple Swapper Hot-Swap Switches SOICN.EPS MAX5911/MAX5912 Package Information Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.