MAX4978, MAX4979, MAX4980, MAX4981 - NEW! - Overvoltage Protector with Active Current Limit

Description

The MAX4978–MAX4981 overvoltage-protection devices protect low-voltage systems against voltage faults up to +28V and feature a low 85mΩ R_ON FET, an active current limiter, and lithium-ion battery overcharge protection (MAX4980/MAX4981). These devices are used to protect the charger input port on a portable device.

The overvoltage protector feature protects against voltages up to 28V with two different trip thresholds: 5.7V (MAX4978/MAX4980/MAX4981) and 6.8V (MAX4979). There is an undervoltage protector with two different trip thresholds: 4.4V (MAX4978) and 2.63V (MAX4979/MAX4980/MAX4981).

The overcurrent limiter and battery voltage monitor features provide a second layer of protection for a lithiumion battery charger. The overcurrent limiter is available in two different thresholds: 0.9A (MAX4978/MAX4979/MAX4980) and 1.95A (MAX4981). Once current reaches the threshold, it is held for a 20ms blanking time. If the current is still at the limit after the blanking time, the FET is turned off, and the device restarts the cycle after 160ms. The battery voltage monitor measures the voltage of a lithium-ion battery and disables the FET if the battery voltage reaches 4.4V (MAX4980/MAX4981).

The MAX4978–MAX4981 are available in a small 8-pin TDFN (2mm x 3mm) package and are specified over the extended -40°C to +85°C temperature range.

Key Features

Applications/Uses

Input Voltage Protection Up to +28V
Integrated nFET Switch, 85mΩ (typ)
Preset Overvoltage Protection Trip Level
- 5.7V (typ) (MAX4978/MAX4980/MAX4981)
- 6.8V (typ) (MAX4979)
Low-Current Undervoltage Lockout Mode
Overcurrent Protection
Internal 160ms (typ) Startup Delay
Thermal-Shutdown Protection
Battery Overcharge Protection (MAX4980/MAX4981)
Startup Debounce Time Indicator (MAX4978/MAX4979)
Small, 8-Pin (2mm x 3mm) TDFN Package

	Cell Phones
	Digital Still Cameras
	MP3 Players
	PDAs and Palmtop Devices

Key Specifications: Overvoltage Protection Controllers

Part Number

Number of Channels

VIN Min (V)

VIN Max (V)

Overvoltage Trip Level (V)

Undervoltage Lockout (V)

GATE Turn-On Time (ms)

GATE Turn Off Time (us)

Features

RoHS Available

Package

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

Price^**

MAX4978 NEW!

2.3

5.7

4.2

1.5

•	Auto Retry

•	Internal Charge Pump

•	Internal Current-Limit Switch

•	Internal Disconnect Switch

•	Soft Start

Yes

THIN QFN (Dual)/8

$1.47 @ 1k

MAX4980 NEW!

•	Auto Retry

•	Internal Charge Pump

•	Internal Current-Limit Switch

•	Internal Disconnect Switch

•	Soft Start

•	Voltage Limiter Mode

$1.47 @ 1k

MAX4981 NEW!

•	Auto Retry

•	Internal Charge Pump

•	Internal Current-Limit Switch

•	Internal Disconnect Switch

•	Soft Start

•	Voltage Limiter Mode

$1.47 @ 1k

See All Overvoltage Protection Controllers (39)

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: 1-6 of 6

MAX4978

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX4978ETA+T

THIN QFN (Dual);8 pin;6 mm²
Dwg: 21-0174B (PDF)
Use pkgcode/variation: T823+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4978ETA+

THIN QFN (Dual);8 pin;6 mm²
Dwg: 21-0174B (PDF)
Use pkgcode/variation: T823+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4980

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX4980ETA+T

THIN QFN (Dual);8 pin;6 mm²
Dwg: 21-0174B (PDF)
Use pkgcode/variation: T823+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4980ETA+

THIN QFN (Dual);8 pin;6 mm²
Dwg: 21-0174B (PDF)
Use pkgcode/variation: T823+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4981

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX4981ETA+T

THIN QFN (Dual);8 pin;6 mm²
Dwg: 21-0174B (PDF)
Use pkgcode/variation: T823+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX4981ETA+

THIN QFN (Dual);8 pin;6 mm²
Dwg: 21-0174B (PDF)
Use pkgcode/variation: T823+1*

-40°C to +85°C

RoHS/Lead-Free: Lead Free
Materials Analysis