AP9060 datasheet(5/9 Pages) DIODES

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AP9060

Document number: DS36001 Rev. 2 - 2

5 of 9

www.diodes.com

August 2012

AP9060

Application Information

Over-Voltage Protection

AP9060 protects sensitive circuits by clamping the input voltage to a safe level. In other words, AP9060 conditions the input voltage before

presenting it to the sensitive circuitry.

The clamp voltage on AP9060 is set to 11.15V (typically at room temperature). Therefore, the sensitive circuitry will not be exposed to a voltage

greater than 11.15V. As a consequence, it is important to ensure that the sensitive ICs that follow AP9060 are safe to operate up to the clamp

voltage level (refer to Figure 4 for variation in clamp voltage over temperature).

If the input voltage is below VCLAMP, the PMOS pass transistor in the AP9060 fully turns on and only I x RON is dropped across the FET (where, I

is the current drawn by the sensitive ICs). On the other hand, if VIN is greater than the clamp voltage, then AP9060 limits the drive to the FET to

ensure that the voltage on VOUT is maintained at the clamp level.

Over-Temperature Protection

As a secondary protection mechanism, AP9060 incorporates an over-temperature shutdown feature. Therefore, if the sensitive circuitry draws

too much current either in normal mode or in the clamp mode, AP9060 will turn off the PMOS transistor, provided the junction temperature

exceeds the thermal shutdown threshold (THMSD). Thereafter, the device will resume normal operation once the junction temperature falls below

THMSD – THMhyst.

In the clamp mode, given that any input voltage above VCLAMP is dropped across the pass transistor in AP9060, care must be taken to keep the

power dissipation within AP9060 in check by minimising the current drawn in this mode.

Fast Input Transient Protection

AP9060 will also protect the sensitive circuits against fast input transients. Upon detecting a fast transient on VIN, AP9060 reduces the drive to

the FET in order to minimise the overshoot on VOUT. With 100nF on VOUT, if the voltage on VIN goes from 0V to 30V in 100ns, the output

voltage will not peak above Vpk.

Reverse Operation

AP9060 supports the USB OTG specification and can operate in the reverse direction as well. Therefore, if the sensitive circuitry drives a voltage

on VOUT (VOUT_REV) and a load is connected on VIN (IIN_REV), then AP9060 will turn the FET on in the reverse direction and only I x RON will be

dropped across the device, similar to the forward operation.

However, note that neither over-voltage nor over-temperature protection mechanisms will function in this mode.

Output Capacitor

It is recommended to have a capacitor on VOUT in a range between 100nF and 10µF.

Output Resistor

It is recommended to have a resistor on VOUT in a range between 10k

Ω and 100kΩ.

AP9060 Datasheet(PDF) 5 Page - Diodes Incorporated