MAX4970 Datasheet, PDF (1/9 Pages) Maxim Integrated Products – Overvoltage-Protection Controllers with a Low RON Internal FET

19-4139; Rev 1; 8/08
Overvoltage-Protection Controllers
with a Low R_ON Internal FET
General Description
The MAX4970/MAX4971/MAX4972 family of overvolt-
age protection devices features a low 40mΩ (typ) R_ON
internal FET and protect low-voltage systems against
voltage faults up to +28V. These devices also drive an
optional external pFET to protect against reverse-polari-
ty input voltages. When the input voltage exceeds the
overvoltage threshold, the internal FET is turned off to
prevent damage to the protected components.
All switches feature a 2.3A (min) current-limit protec-
tion. During a short-circuit occurrence, the device oper-
ates in an autoretry mode where the internal MOSFET is
turned on to check if the fault has been removed. The
autoretry interval time is 15ms, and if the fault is
removed, the MOSFET remains on.
The MAX4970/MAX4971/MAX4972 feature an enable
input (EN) that controls the operation of the internal
nFET as well as the optional external pFET. The use of
EN allows the external pFET to block reverse voltages
independent of any signal present at the output.
The overvoltage thresholds (OVLO) are preset to
4.65V (MAX4972), 5.8V (MAX4970), or 6.35V (MAX4971).
The undervoltage thresholds (UVLO) are preset to 2.45V.
When the input voltage drops below the UVLO, the
devices enter a low-current standby mode.
All devices are offered in a small 12-bump, WLP pack-
age and operate over the -40°C to +85°C extended
temperature range.
Applications
Cell Phones
Digital Still Cameras
PDAs and Palmtop Devices
MP3 Players
Features
♦ Input Voltage Protection up to +28V
♦ Integrated nFET Switch
♦ Reverse Voltage Protection with External pFET
♦ Enable Input
♦ Preset Overvoltage Protection Trip Level
5.8V (MAX4970)
6.35V (MAX4971)
4.65V (MAX4972)
♦ Low-Current Undervoltage-Lockout Mode
♦ Short-Circuit Protection (Autoretry)
♦ Internal 15ms Startup Delay and Retry Times
♦ Input-Voltage Power-Good Logic Output
♦ Thermal-Shutdown Protection
♦ 2mm x 1.5mm, 12-Bump WLP Package
Pin Configuration
TOP VIEW (BUMPS ON BOTTOM)
1
2
3
4
MAX4970/MAX4971/MAX4972
A
ACOK
OUT
OUT
OUT
B
GND
OUT
IN
GP
C
EN
IN
IN
IN
WLP
Ordering Information/Selector Guide
PART
MAX4970EWC+T
MAX4971EWC+T
MAX4972EWC+T
PIN-PACKAGE
12 WLP
12 WLP
12 WLP
TOP MARK
AAA
AAB
AAC
PACKAGE CODE
W121A2+1
W121A2+1
W121A2+1
UVLO (V)
2.45
2.45
2.45
Note: All devices are specified over the -40°C to +85°C operating temperature range.
+Denotes a lead-free/RoHS-compliant package.
T = Tape-and-reel package.
OVLO (V)
5.8
6.35
4.65
ACOK ACTION
UVLO only
UVLO only
UVLO and OVLO
Typical Operating Circuit appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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or visit Maxim’s website at www.maxim-ic.com.