AP2553W6-7 Diodes Inc., AP2553W6-7 Datasheet - Page 11

• Manufacturer Part Number: AP2553W6-7
• Description: Power Switch ICs - USB 2.1A Precision ADJ 5.5V 2.1A 210kOhm
• Manufacturer: Diodes Inc.

Specifications of AP2553W6-7

• Rohs: yes
• Supply Voltage - Min: 2.7 V
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 150 C
• Minimum Operating Temperature: - 40 C
• Package / Case: SOT26
• Mounting Style: SMD/SMT
• Number Of Switches: Single
• Off Time (max): 0.5 ms
• On Resistance (max): 70 mOhms
• On Time (max): 1.5 ms
• Operating Temperature Range: - 40 C to + 150 C
• Supply Current: 2.1 A
• Switch Configuration: Single

Application Note
Reverse-Current and Reverse-Voltage Protection
For AP2552A/53A, once ROVP is activated and when the condition exists for more than 5ms (TYP), output device is disabled and shutdown.
This is called the "Time from Reverse-Voltage Condition to MOSFET Turn Off”. FAULT assertion occurs at a de-glitch time of 4ms after ROVP is
reached. Recovery from this fault is achieved by recycling power or toggling EN. FAULT de-assertion de-glitch time is same as the de-assertion
time.
Special Functions:
Discharge Function
When enable is de-asserted, or when the input voltage is under UVLO level, the discharge function is active. The output capacitor is discharged
through an internal NMOS that has a discharge resistance of 100Ω. Hence, the output voltage drops down to zero. The time taken for discharge
is dependent on the RC time constant of the resistance and the output capacitor.
FAULT Response
The FAULT open-drain output goes active low for any of following faults: Current limit threshold, short- circuit current limit, reverse-voltage
condition or thermal shutdown. The time from when a fault condition is encountered to when the FAULT output goes low is 7ms (TYP). The
FAULT output remains low until over-current, short-circuit current limit and over-temperature conditions are removed. Connecting a heavy
capacitive load to the output of the device can cause a momentary Over-current condition, which does not trigger the FAULT due to the 7ms
deglitch timeout. This 7-ms timeout is also applicable for over-current recovery and over-temperature recovery. The AP2552/53 and
AP2552-2/53A are designed to eliminate erroneous over-current reporting without the need for external components, such as an RC delay
network.
For the AP2552/53 and AP2552A/53A when the reverse voltage condition is triggered, FAULT output goes low after 4ms (TYP). This 4ms (TYP)
timeout is also applicable for the recovery from reverse voltage fault.
When the ILIM pin is shorted to IN or GND, current-limit threshold and short-circuit current limit will be clamped at typically 75mA.When the ILIM
pin is shorted to IN or GND the AP2552/53 and AP2552A/53A FAULT pin will not assert during current limiting conditions; The FAULT pin will
assert during short circuit conditions.
Power Supply Considerations
A 0.01-μF to 0.1-μF X7R or X5R ceramic bypass capacitor between IN and GND, close to the device, is recommended. This limits the input
voltage drop during line transients. Placing a high-value electrolytic capacitor on the input (10μF minimum) and output pin(120µF) is
recommended when the output load is heavy. This precaution also reduces power-supply transients that may cause ringing on the input.
Additionally, bypassing thedeviceoutput with a 0.1μF to 4.7μF ceramic capacitor improves the immunity of the device to short-circuit transients.
This capacitor also prevents output from going negative during turn-off due to parasiticinductance.
Power Dissipation and Junction Temperature
The low on-resistance of the internal MOSFET allows the small surface-mount packages to pass large current. Using the maximum operating
ambient temperature (T
Finally, calculate the junction temperature:
Where:
Generic Hot-Plug Applications
In many applications it may be necessary to remove modules or pc boards while the main unit is still operating. These are considered hot-plug
applications. Such implementations require the control of current surges seen by the main power supply and the card being inserted. The most
effective way to control these surges is to limit and slowly ramp the current and voltage being applied to the card, similar to the way in which a
power supply normally turns on. Due to the controlled rise times and fall times of the AP2552/53 AND AP2552A/53A, these devices can be used
to provide a softer start-up to devices being hot-plugged into a powered system. The UVLO feature of the AP2552/53 AND AP2552A/53A also
ensures that the switch is off after the card has been removed, and that the switch is off during the next insertion.
AP2552/AP2553/AP2552A/AP2553A
Document number: DS35404 Rev. 6 - 2
P
T
T
θ
P
JA
D
J
A
D
= P
= Ambient temperature °C
= R
= Total power dissipation
= Thermal resistance
D
DS(ON)
x θ
JA
× I
A
+ T
) and R
2
A
(cont.)
DS(ON)
, the power dissipation can be calculated by:
(cont.)
www.diodes.com
11 of 16
AP2552/ AP2553/ AP2552A/ AP2553A
© Diodes Incorporated
April 2013