MAX4920BETD+T Maxim Integrated Products, MAX4920BETD+T Datasheet - Page 8

• Manufacturer Part Number: MAX4920BETD+T
• Description: IC CTLR OVP/OCP BATT PWR 14-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX4920BETD+T

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 14-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

An internal 5.5V supply powers the on-chip charge
pump used to drive GN1 above IN, allowing the use of
a low-cost nFET. The GN1 voltage is approximately two
times V
clamps to 9.5V (MAX4919B/MAX4920B) or 8.1V
(MAX4921B).
ACOK is an active-low open-drain output that asserts
when V
period. ACOK deasserts immediately to overvoltage
and undervoltage faults. Connect a pullup resistor from
ACOK to the logic I/O voltage of the host system.
PWR_ON is one of the logic inputs that enables the
internal 1.8A switch. Drive PWR_ON high to turn on the
internal switch. PWR_ON also controls the logic output
Battery Power-Up Logic with Overvoltage
and Overcurrent Protection
Figure 1. ACOK One-Shot Timing Diagram
8
_______________________________________________________________________________________
IN
UVLO
until V
<V
IN
IN
exceeds 5.5V, at which point, GN1
< V
OVLO
ONE-SHOT
ADAPTER
STATUS
VOLTAGE
ACOK
P2
ACOK
IN
for the 25ms debounce
OVLO
UVLO
GN1 Driver
25ms DEBOUNCE PERIOD
PWR_ON
OFF
ACOK
ONOK. The ONOK open-drain output is the inverse of
the PWR_ON input state (see Figure 5). Note that
ONOK is high impedance when V
< 2.82V (typ). If V
less than 2.82V (typ), PWR_ON and ONOK are dis-
abled and ONOK pulls high. When BTI rises above
2.82V (typ) again, PWR_ON is again enabled and
ONOK goes back to its previous logic level before a
low condition at BTI (see Figure 6).
An internal 1.8A (min) pFET with a 100mΩ (typ) R
connects BTI to the load at BTO. The internal battery
switchover FET turns on when either HP_PWR,
PWR_ON, or PWR_HOLD is high. Note that when BTI
< 2.15V, the internal switch remains inactive, regard-
less of the logic control signals.
t
1SHAC
ON
OFF
BTI
is greater than 2.15V (typ), but
Battery Switchover
IN
< V
UVLO
, and V
BTI
ON