Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - hot swap controller Multi-purpose uMAX 10 Surface-mount

19-3443; Rev 3; 4/10

1V to 13.2V, n-Channel Hot-Swap Controllers

Require No Sense Resistor

MAX5925

MAX5926

SC_DET

GND

REMOVABLE CARD

2.25V TO 13.2V

BACKPLANE

CB SENSEGATE

GND

1V TO V

OUT

SEE FIGURE 1 FOR A DETAILED TYPICAL OPERATING CIRCUIT WITHOUT R

SENSE

TYPICAL OPERATION WITHOUT R

SENSE

General Description

The MAX5924/MAX5925/MAX5926 1V to 13.2V hot-swap

controllers allow the safe insertion and removal of circuit

cards into live backplanes. These devices hot swap sup-

plies ranging from 1V to 13.2V provided that the device

supply voltage, V

, is at or above 2.25V and the hot-

swapped supply, V

, does not exceed V

The MAX5924/MAX5925/MAX5926 hot-swap controllers

limit the inrush current to the load and provide a circuit-

breaker function for overcurrent protection. The devices

operate with or without a sense resistor. When operat-

ing without a sense resistor, load-probing circuitry

ensures a short circuit is not present during startup,

then gradually turns on the external MOSFET. After the

load probing is complete, on-chip comparators provide

overcurrent protection by monitoring the voltage drop

across the external MOSFET on-resistance. In the event

of a fault condition, the load is disconnected.

The MAX5924/MAX5925/MAX5926 include many inte-

grated features that reduce component count and

design time, including configurable turn-on voltage,

slew rate, and circuit-breaker threshold. An on-board

charge pump provides the gate drive for a low-cost,

external n-channel MOSFET.

The MAX5924/MAX5925/MAX5926 are available with

open-drain PGOOD and/or PGOOD outputs. The

MAX5925/MAX5926 also feature a circuit breaker with

temperature-compensated R

DS(ON)

sensing. The

MAX5926 features a selectable 0ppm/°C or 3300ppm/°C

temperature coefficient. The MAX5924 temperature coef-

ficient is 0ppm/°C and the MAX5925 temperature coeffi-

cient is 3300ppm/°C. Autoretry and latched fault-

management configurations are available (see the

Selector Guide

Applications

Base Stations

RAID

Remote-Access Servers

Network Routers and Switches

Servers

Portable Device Bays

Features

o Hot Swap 1V to 13.2V with V

≥ 2.25V

o Drive High-Side n-Channel MOSFET

o Operation With or Without R

SENSE

o Temperature-Compensated R

DS(ON)

Sensing

o Protected During Turn-On into Shorted Load

o Adjustable Circuit-Breaker Threshold

o Programmable Slew-Rate Control

o Programmable Turn-On Voltage

o Autoretry or Latched Fault Management

o 10-Pin µMAX

or 16-Pin QSOP Packages

MAX5924/MAX5925/MAX5926

________________________________________________________________

Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

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

Typical Operating Circuits

Ordering Information

EVALUATION KIT

AVAILABLE

Selector Guide appears at end of data sheet.

Pin Configurations appear at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX5924AEUB -40°C to +85°C 10 µMAX

MAX5924BEUB -40°C to +85°C 10 µMAX

MAX5924CEUB* -40°C to +85°C 10 µMAX

MAX5924DEUB* -40°C to +85°C 10 µMAX

MAX5925AEUB -40°C to +85°C 10 µMAX

MAX5925BEUB* -40°C to +85°C 10 µMAX

MAX5925CEUB* -40°C to +85°C 10 µMAX

MAX5925DEUB* -40°C to +85°C 10 µMAX

MAX5926EEE -40°C to +85°C 16 QSOP–EP**

Typical Operating Circuits continued at end of data sheet.

Future product—contact factory for availability.

EP = Exposed pad.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Summary of content (21 pages)

PAGE 1
KIT ATION EVALU E L B A IL AVA 19-3443; Rev 3; 4/10 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor The MAX5924/MAX5925/MAX5926 1V to 13.2V hot-swap controllers allow the safe insertion and removal of circuit cards into live backplanes. These devices hot swap supplies ranging from 1V to 13.2V provided that the device supply voltage, VCC, is at or above 2.25V and the hotswapped supply, VS, does not exceed VCC.
PAGE 2
MAX5924/MAX5925/MAX5926 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND, unless otherwise noted.) VCC .........................................................................-0.3V to +14V GATE*.....................................................................-0.3V to +20V All Other Pins ............-0.3V to the lower of (VCC + 0.3V) or +14V SC_DET Current (200ms pulse width, 15% duty cycle) ...
PAGE 3
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor (VCC, EN (MAX5924/MAX5925), EN1 (MAX5926) = +2.7V to +13.2V; EN2 (MAX5926) = 0V; VS (see Figure 1) = +1.05V to VCC; TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = 5V, RL = 500Ω from OUT to GND, CL = 1µF, SLEW = open, TA = +25°C, unless otherwise noted.
PAGE 4
ELECTRICAL CHARACTERISTICS (continued) (VCC, EN (MAX5924/MAX5925), EN1 (MAX5926) = +2.7V to +13.2V; EN2 (MAX5926) = 0V; VS (see Figure 1) = +1.05V to VCC; TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = 5V, RL = 500Ω from OUT to GND, CL = 1µF, SLEW = open, TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.6 1.6 3.
PAGE 5
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor CIRCUIT-BREAKER CURRENT vs. SUPPLY VOLTAGE (TC = 3300ppm/°C) CIRCUIT-BREAKER CURRENT vs. HOT-SWAP VOLTAGE VCC = VS 5.5 TC = 3300ppm/°C 52 VCC = 5.0V 55 MAX5924 toc05 56 MAX5924 toc04 6.0 MAX5924 toc06 GATE DRIVE VOLTAGE vs. TEMPERATURE VCC = VS 53 VCC = 3.0V 4.5 48 ICB (µA) CB (µ ) VGS (V) 5.0 51 44 VCC = 13.2V 3.0 VCC = 13.
PAGE 6
MAX5924/MAX5925/MAX5926 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor Typical Operating Characteristics (continued) (VCC = 5V, CL = 1µF, CSLEW = 330nF, CGATE = 10nF, RL = 500Ω, Figure 1, TA = +25°C, unless otherwise noted.
PAGE 7
1V to 13.
PAGE 8
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor MAX5924/MAX5925/MAX5926 Pin Description PIN MAX5924A/ MAX5924B/ MAX5924C/ MAX5924D/ MAX5926 MAX5925A/ MAX5925B/ MAX5925C MAX5925D 1 8 1 1 NAME VCC FUNCTION Power-Supply Input. Connect VCC to a voltage between 2.47V and 13.2V. VCC must always be equal to or greater than VS (see Figure 1). 2 2 2 SC_DET Short-Circuit Detection Output. Connect SC_DET to VOUT through a series resistor, RSC, when not using RSENSE.
PAGE 9
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor VS VCC MAX5924/MAX5925/MAX5926 BACKPLANE REMOVABLE CARD 1V TO VCC 2.25V TO 13.2V RSC RCB 20kΩ 10Ω CB GATE SENSE V+ OUT VCC ON (ON*) SC_DET 1µF GND MAX5925 MAX5926 EN (EN1**) EN2** EN EN2 TC** CL PGOOD** PGOOD (PGOOD*) GND SLEW LATCH** GND CSLEW *MAX5925A AND MAX5925C. **MAX5926. DC-DC CONVERTER Figure 1. Typical Operating Circuit (Without RSENSE) BACKPLANE REMOVABLE CARD RSENSE 1V TO VCC VS 2.25V TO 13.
PAGE 10
MAX5924/MAX5925/MAX5926 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor GATE 50kΩ VCC CHARGE PUMP VZ = 9V SLEW N A MAX5924 MAX5925 MAX5926 2µA VCC RLP N VCB,TH CB SC_DET SLOW COMPARATOR VS 75kΩ OUT TIMER RCBF 0.2V VCBF,TH 75kΩ FAST COMPARATOR OSCILLATOR ICB TC*** PGOOD* LOGIC CONTROL SENSE PGOOD** LATCH*** VCC EN/(EN1***) VCC 0.8V VCC GND 1.24V EN2*** *MAX5924B, MAX5924D, MAX5925B, MAX5925D, MAX5926 ONLY. **MAX5924A, MAX5924C, MAX5925A, MAX5925C, MAX5926 ONLY.
PAGE 11
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor The MAX5924/MAX5925/MAX5926 are hot-swap controller ICs designed for applications where a line card is inserted into a live backplane. Normally, when a line card is plugged into a live backplane, the card’s discharged filter capacitors provide a low impedance that can momentarily cause the main power supply to collapse.
PAGE 12
Load Probing Normal Operation The MAX5924/MAX5925/MAX5926 load-probing circuitry detects short-circuit conditions during startup. Load probing is active only when no external R SENSE is detected. As the device begins load probing, SC_DET is connected to VCC through an internal switch with an on-resistance of RLP (Figure 6). VCC then charges the load with a probe current limited at ≈200mA. (Figure 1) IPROBE = (VCC - VOUT)/(RLP + RSC) If the load voltage does not reach VLP,TH (0.
PAGE 13
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor Slow Comparator The slow comparator is disabled during startup while the external MOSFET turns on. If the slow comparator detects an overload condition while in normal operation (after startup is complete), it turns off the external MOSFET by discharging the gate capacitance with I GATE,PD . The magnitude of I GATE,PD depends on the external MOSFET gate-to-source voltage, VGS.
PAGE 14
Undervoltage Lockout (UVLO) UVLO circuitry prevents the MAX5924/MAX5925/ MAX5926 from turning on the external MOSFET until VCC exceeds the UVLO threshold, VUVLO, for tD,UVLO. UVLO protects the external MOSFET from insufficient gate-drive voltage, and tD,UVLO ensures that the board is fully plugged into the backplane and VCC is stable prior to powering the hot-swapped system.
PAGE 15
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor The enable comparators control the on/off function of the MAX5924/MAX5925/MAX5926. Enable is also used to reset the fault latch in latch mode. Pull EN or EN1 low for 100µs to reset the latch. A resistive divider between EN or EN1, VS, and GND sets the programmable turnon voltage to a voltage greater than VUVLO (Figure 10).
PAGE 16
MAX5924/MAX5925/MAX5926 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor To determine the proper circuit-breaker resistor value use the following equation, which refers to Figure 12: RCB = (ITRIPSLOW x RDS(ON)( T)) + VCB ,OS ICB where ITRIPSLOW is the desired slow-comparator trip current. The fast-comparator trip current is determined by the selected RCB value and cannot be adjusted independently.
PAGE 17
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor Applications Information Component Selection n-Channel MOSFET Most circuit component values may be calculated with the aid of the MAX5924–MAX5926. The "Design calculator for choosing component values" software can be downloaded from the MAX5924–MAX5926 Quickview on the Maxim website. Select the external n-channel MOSFET according to the application’s current and voltage level. Table 3 lists some recommended components.
PAGE 18
MAX5924/MAX5925/MAX5926 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor Table 4. Component Manufacturers COMPONENT Sense Resistors MOSFETs MANUFACTURER PHONE Dale-Vishay 402-564-3131 IRC 828-264-8861 www.irctt.com Fairchild 888-522-5372 www.fairchildsemi.com International Rectifier 310-233-3331 www.irf.
PAGE 19
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor the two devices are equal, the circuit-breaker trip threshold is most accurate. Keep the MOSFET and the MAX5925/MAX5926 as close to each other as possible to facilitate thermal coupling. HIGH-CURRENT PATH SENSE RESISTOR RCB MAX5924 MAX5925 MAX5926 Figure 15.
PAGE 20
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor MAX5924/MAX5925/MAX5926 Pin Configurations TOP VIEW VCC 1 16 CB SC_DET 2 VCC 1 SC_DET 2 EN 3 PGOOD (PGOOD) GND 10 CB 9 SENSE 8 OUT 4 7 GATE 5 6 SLEW MAX5924 MAX5925 GND 5 9 Chip Information TRANSISTOR COUNT: 3751 PROCESS: BiCMOS N VOUT Package Information SENSE GATE OUT VCC MAX5924 MAX5926 For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
PAGE 21
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor REVISION NUMBER REVISION DATE 0 8/05 Initial release 1 6/06 Revised data sheet title, General Description, Features, EC table, Typical Operating Circuit, and added No-Load Operation section. 1–13, 15–18 2 10/06 Initial release of MAX5924BEUB and revised EC table. 1–4, 10–12 3 4/10 Revised EC table.