MAX15091 Datasheet, PDF (8/15 Pages) Maxim Integrated Products – Solution with Current Report Output

MAX15091/MAX15091A
2.7V to 18V, 9A, Integrated Hot-Swap
Solution with Current Report Output
Pin Description (continued)
PIN
NAME
FUNCTION
Enable Timer Input. Connect a capacitor between CDLY and GND to set a 1s/µF duration timeout
10
CDLY delay. The EN input has to be pulled low before the timeout delay elapses, to prevent internal
MOSFET shutdown after power-up.
Enable Input. Externally pulled up to logic-high state through a resistor normally connected to REG. The
EN input must be pulled down (for at least 1ms) by the external circuit before a programmable timeout
11
EN
delay has elapsed, otherwise a shutdown occurs. The timeout timer starts counting when the internal
MOSFET is turned on. Connect a capacitor between CDLY and GND to program the duration of the
timeout delay. Connect EN to GND to disable this feature.
12
13
14, 25, 26
15–21
22
23
24
27
28
FAULT
PG
GND
OUT
OV
UV
REG
CB
ISENSE
Fault Status Output. FAULT is an open-drain, active-low output. FAULT asserts low when an overcurrent
or overtemperature condition triggers a shutdown. FAULT is disabled during startup.
Power-Good Output. PG is an open-drain, active-high output. PG pulls low until the internal power
MOSFET is fully enhanced.
Ground
Load Output. Source of the internal power MOSFET.
Overvoltage Enable Input. Pull OV high to turn off the internal MOSFET. Connect OV to an external
resistive divider to set the overvoltage-disable threshold. See the Setting the Overvoltage Threshold
section.
Active-High Enable Comparator Input. Pulling UV high enables the internal MOSFET to turn on. UV also
sets the undervoltage threshold. See the Setting the Undervoltage Threshold section.
Internal Regulator Output. Bypass to ground with a 1µF capacitor. Do not power external circuitry using
the REG output (except a resistor > 50kΩ connected from REG to EN).
Current-Limit Threshold Set. Connect a resistor from CB to GND to set the circuit-breaker threshold. Maximum
value of 25kΩ can be accepted for safe operation. Having the CB pin connected to GND sets the circuit-
breaker threshold at 0A.
Current-Sense Output. The ISENSE output sources a current that is proportional to the output current.
Connect a resistor between ISENSE and GND to produce a scaled voltage.
Exposed Pad. Connect EP to GND externally. Do not use EP as an electrical connection to GND. EP
—
EP
is internally connected to GND through a resistive path and must be connected to GND externally. To
optimize power dissipation, solder the exposed pad to a large copper power plane. Do not leave EP
unconnected.
Detailed Description
Enable Logic and Undervoltage/
Overvoltage-Lockout Threshold
The MAX15091/MAX15091A ICs enable the output, as
shown in Table 1. The devices are ready to drive the out-
put when the V_CC supply rises above the V_UVLO thresh-
old. The devices turn on the output when V_CC > V_UVLO,
V_UV is high (V_UV > 1.2V) and V_OV is low (V_OV < 1.2V).
The devices turn off the output when V_UV falls below
(1.2V - V_{UV_HYS}) or V_OV rises above 1.2V. An external
resistive divider from IN to UV, OV, and ground provide
the flexibility to set the undervoltage/overvoltage-lockout
threshold to any desired level between V_UVLO and 18V.
See Figure 1 and the Setting the Undervoltage Threshold
and Setting the Overvoltage Threshold sections.
www.maximintegrated.com
Maxim Integrated │  8