MAX5944 Dual FireWire Current Limiter and Low-Drop ORing Switch Controller

Description

The MAX5944 is a dual, current limiter/low-drop ORing, switch controller power-management IC for FireWire® applications. Each independent channel controls two external power MOSFETs to regulate current from the input power supply to the load and performs low-voltagedrop power-supply ORing. The MAX5944 operates over the 7.5V to 37V input range and provides inrush and output current limit in addition to diode ORing functions suitable for FireWire applications.

The MAX5944 allows the safe insertion and removal of FireWire peripherals into a live FireWire port by providing inrush current control and output current-limiting functions. The MAX5944 features a current-limit function that actively limits the current drawn by the load with a 2ms timeout. Its autoretry function then automatically restarts after the 259ms autoretry delay time.

The ORing feature provides a very efficient way to protect the FireWire port when connected to another FireWire peripheral that sources a higher voltage. By turning off the external MOSFETS, the MAX5944 provides a true bidirectional load disconnect. Each channel has an independent ON/OFF control that results in less than 10µA supply current per channel.

The MAX5944 operates over the -40°C to +85°C extended temperature range and is available in a 16-pin SO package.

Key Features

Applications/Uses

Provides Safe Hot-Swap for 7.5V to 37V Power Supplies
Dual-Channel Hot-Swap
Low-Drop Power ORing with Ultra-Fast Turn-Off
Active Current Limit
±5% Current-Limit Sensing Accuracy
2ms Current-Limit Timeout
Fast Current-Limit Response to Output Short-Circuit Conditions
Drives External n-Channel Power MOSFETs
Independent Overcurrent Fault Status Outputs
259ms Autoretry Period
10µA (Per Channel) Shutdown Current
Independent ON/OFF Control Allows Undervoltage Lockout Programming
Fast Load Disconnect Control Through ON/OFF Inputs
Bidirectional Load Disconnect
Power Routing from One Port to Another

	FireWire® Desktop/Notebook Port
	FireWire® Hub
	FireWire® Peripheral Device Current Limit
	Hot Swap

Key Specifications: Hot Swap Controllers

Part Number

Min. V_IN (V)

Max. V_IN (V)

Low Voltage

High Voltage

Voltage Polarity

Type

Fault Condition Control

Number of Channels

Features

RoHS Available

Package

Smallest Available Package (max w/pins) (mm²)

Operating Temp. Range (°C)

Price^**

MAX5944

7.5

Yes

Positive

Positive, Low-Voltage

Periodic retry

•	125mA Fast Gate Pulldown Current

•	2ms Default Current-Limit Timeout

•	Bi-Directional Load Disconnect

•	Dual Firewire Controller

•	Fault Status Output Active Low

•	In-Rush Current and Short Circuit Protection

•	Powers up into shorted load

•	Programmable In-Rush and Short-Circuit Protection

Yes

SOIC/16

-40 to +85

$1.56 @ 1k

See All Hot Swap Controllers (44)

Key Specifications: ORing MOSFET Controllers

Part Number

Reverse Current Protection

Under-Voltage Protection

Charge-Pump Capacitor

Soft Start

Enable

Fault Indicator

EV-Kit

RoHS Available

Package

Smallest Available Package (max w/pins) (mm²)

Operating Temp. Range (°C)

Price^**

MAX5944

Yes

SOIC/16

-40 to +85

$1.56 @ 1k

See All ORing MOSFET Controllers (5)

Notes:
^**This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Ordering Information

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Devices: 1-4 of 4

MAX5944

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX5944ESE

SOIC;16 pin;62 mm²
Dwg: 21-0041B (PDF)
Use pkgcode/variation: S16M-6*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX5944ESE-T

SOIC;16 pin;62 mm²
Dwg: 21-0041B (PDF)
Use pkgcode/variation: S16M-6*

-40°C to +85°C

RoHS/Lead-Free: No
Materials Analysis

MAX5944ESE+

SOIC;16 pin;62 mm²
Dwg: 21-0041B (PDF)
Use pkgcode/variation: S16M+6*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX5944ESE+T

SOIC;16 pin;62 mm²
Dwg: 21-0041B (PDF)
Use pkgcode/variation: S16M+6*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

Related Products

MAX5943 FireWire Current Limiter and Low-Drop ORing Switch Controller
MAX5902, MAX5903 +72V SOT23/TDFN Simple Swapper Hot-Swap Controllers
MAX4271, MAX4272, MAX4273 3V to 12V, Current-Limiting, Hot Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection