MAX15090_13 Datasheet, PDF (12/15 Pages) Maxim Integrated Products – 2.7V to 18V, 12A, Hot-Swap Solution with Current Report Output

MAX15090/MAX15090A
2.7V to 18V, 12A, Hot-Swap Solution
with Current Report Output
Thermal Protection
The devices enter a thermal-shutdown mode in the event
of overheating caused by excessive power dissipation
or high ambient temperature. When the junction tem­
perature exceeds T_J = +150NC (typ), the internal thermal-
protection circuitry turns off the internal power MOSFET.
The devices recover from thermal-shutdown mode once
the junction temperature drops by 20NC (typ).
IN to OUT Short-Circuit Protection
At startup, after all the input conditions are satisfied (UV,
OV, V_UVLO), the devices immediately check for an IN to
OUT short-circuit fault. If V_OUT is greater than 90% of
V_IN, the internal MOSFET cannot be turned on so FAULT
is asserted and the MAX15090A enters autoretry mode in
3.2s, while the MAX15090 latches off.
If V_OUT is lower than 90% of V_IN but greater than 50%
of V_IN, the internal MOSFET still cannot be turned on. No
fault is asserted and the MOSFET can turn on as soon as
V_OUT is lower than 50% of V_IN.
Applications Information
Setting the Undervoltage Threshold
The devices feature an independent on/off control (UV)
for the internal MOSFET. The devices operate with a 2.7V
to 18V input voltage range and have a default 2.5V (typ)
undervoltage-lockout threshold.
The internal MOSFET remains off as long as V_CC < 2.5V
or V_UV < V_{UV_TH}. The undervoltage-lockout threshold is
prog­ rammable using a resistive divider from IN to UV,
OV, and GND (Figure 1). When V_CC is greater than 2.7V
and V_UV exceeds the 1.23V (typ) threshold, the internal
MOSFET turns on and goes into normal operation. Use
the following equation to calculate the resistor values for
the desired undervoltage threshold:
= R1


V_IN
V_{UV_TH}
−

1
×
(R2
+
R3
)
where V_IN is the desired turn-on voltage for the output
and V_{UV_TH} is 1.23V. R1 and (R2 + R3) create a resistive
divider from IN to UV. During normal operating condi-
tions, V_UV must remain above its 1.23V (typ) threshold.
If V_UV falls 100mV (V_{UV_HYS}) below the threshold, the
internal MOSFET turns off, disconnecting the load from
the input.
Setting the Overvoltage Threshold
The devices also feature an independent overvoltage-
enable control (OV) for the internal MOSFET.
When V_OV exceeds the 1.23V (typ) threshold, the internal
MOSFET turns off.
The overvoltage-lockout threshold is prog­rammable
using a resistive divider from IN to UV, OV, and GND
(Figure 1). Use the following equation to calculate the
resistor values for the desired overvoltage threshold:
= (R1+ R2)


V_IN
V_{OV_TH}

− 1 × R3
where V_IN is the desired turn-off voltage for the output
and V_{OV_TH} is 1.23V. R1 and (R2 + R3) create a resistive
divider from IN to OV. During normal operating condi-
tions, V_OV must remain below its 1.23V (typ) threshold.
If V_OV rises above the V_{OV_TH} threshold, the internal
MOSFET turns off and disconnects the load from the
input.
Wafer-Level Packaging (WLP)
Applications Information
For the latest application details on WLP construction,
dimensions, tape carrier information, PCB techniques,
bump-pad layout, recommended reflow temperature
profile, as well as the latest information on reliability test-
ing results, refer to Application Note 1891: Wafer-Level
Packaging (WLP) Applications Information, available at
www.maximintegrated.com/wlp.
Maxim Integrated
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