MAX4893BETB+T Maxim Integrated Products, MAX4893BETB+T Datasheet - Page 7

• Manufacturer Part Number: MAX4893BETB+T
• Description: IC CTLR OVP CURR LIMIT 10-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX4893BETB+T

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 10-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 2. Shutdown Timing Diagram
The MAX4881–MAX4884/MAX4893B provide up to
+28V overvoltage protection for low-voltage systems.
When the input voltage at IN exceeds the overvoltage
trip level (OVLO), the MAX4881–MAX4884/MAX4893B
turn off the low-cost external n-channel FET to prevent
damage to the protected components and issue an
overvoltage fault flag.
The MAX4881–MAX4884 feature a built-in current-limited
switch that limits the load current to 1.1A (MAX4881/
MAX4882), 0.7A (MAX4883B/MAX4883C/MAX4884B/
MAX4884C), and 0.9A (MAX4893B). When the load cur-
rent is at the current limit for longer than the blanking
time, the switch of the MAX4881/MAX4882/MAX4883B/
MAX4884B/MAX4893B latches off and does not turn
back on until EN or CB or IN is cycled. A current-limit flag
(FLAGI) asserts to indicate a current fault condition. The
MAX4883C/MAX4884C limit the current to 0.7A indefinite-
ly until the thermal protection trips. An overcurrent flag
output asserts to indicate a current fault condition after
the blanking time has elapsed.
Figure 1. Startup Timing Diagram
V
7V/8V
4V/5V
V
IN
V
1.2V
GATE
V
GATE
V
V
OV
IN
OV
V
V
OVLO
UVLO
_______________________________________________________________________________________
Overvoltage Protection Controllers with
t
START
t
GOFF
Detailed Description
0.3V
0.3V
t
GON
t
OV
t
5V
0V-BLANK
8V
2.4V
0.4V
The MAX4881/MAX4883/MAX4893B have a fixed 4.35V
undervoltage lockout level (UVLO) while the
MAX4882/MAX4884 have a fixed UVLO of 2.55V. GATE
goes low when V
external n-channel FET.
The MAX4881/MAX4883/MAX4893B have a fixed 5.6V
overvoltage threshold (OVLO), while the MAX4882/
MAX4884 have a fixed OVLO of 4.5V. GATE goes low
when V
n-channel FET.
The OV output signals the host system that there is a fault
with the input voltage. OV asserts low in response to
either an overvoltage or undervoltage fault. OV stays low
for 50ms after GATE turns on, before deasserting high.
OV is an open-drain active-low output. Connect a
pullup resistor from OV to the logic I/O voltage of the
host system or to any voltage source up to 6V. Driving
EN high disables OV.
Figure 3. Power-Up Overvoltage Timing Diagram
Figure 4. Disable Timing Diagram
Current Limit in TDFN
I
GATE
V
0V
IN
V
GATE
V
IN
EN
is higher than V
IN-Undervoltage Lockout (UVLO)
V
IN-Overvoltage Lockout (OVLO)
OVLO
2.4V
IN
t
OVP
t
is below V
DIS
OVLO
Fault Flag Output (
80%
0.3V
, turning off the external
UVLO
, turning off the
OV )
7