Rev. G 06/16

5

CHY103

www.power.com

Figure 10. Optional Thermal Monitor Through NTC Resistor.

Figure 9. Remote System Level Check Flowchart.

through a 150 µA current source. This signal can for instance be

used to initiate hysteretic shutdown in a power supply employing

InnoSwitch through circuitry Q1, Q2, D1, and R3 as shown in Figure 5.

Alternatively a primary-side latching shutdown can be configured by

driving optocoupler U3 through Q1 and R5 as depicted in Figure 8.

The FA/P pin is clamped internally to 1 V during normal operation.

Adaptive Output Overvoltage Protection

CHY103 monitors the voltage present at the FEEDBACK DRIVE pin in

order to prevent excessive output voltage levels in case the power

supply control loop lost regulation. The OV comparator threshold

V

9 V, 12 V, or 20 V) outside Quick Charge 3.0 continuous mode. As

soon as the output voltage reaches 120% of the set output voltage

CHY103 activates the protection mode if the OV fault is present for at

least 50 µs. Adaptive OVP is blanked for 500 ms when set output

voltage is stepped down outside of continuous mode (for instance

from 9 V to 5 V).

In Quick Charge 3.0 continuous mode the OV comparator threshold is

fixed to the respective maximum output voltage set by resistor R

The resulting actual output OV level V

depends on the respective voltage V

.

VV

V

24

OUTOVOUT SET

=+

^^

hh

System Level Fault Protection

CHY103 offers an optional system level check to verify that power

delivered by the power supply is not caused by a possible soft-short

circuit present at the output but is requested by a connected PD. The

system fault check is either activated automatically by CHY103 when

no PD is connected (D+ is below 0.325 V) or can be initiated remotely

through the connected PD as outlined in the flowchart shown in Figure 9.

The FAULT MONITOR/PROTECTION pin monitors the switching

frequency of InnoSwitch through a voltage to frequency converter R

FR

and C

PROTECTION pin exceeds 0.325 V, a fault is flagged and CHY103

activates the protection mode if the fault is present for at least 40 ms.

The fault monitor input is only active when no PD is connected (D+ is

below 0.325 V) or a connected PD initiates a remote system level

R4

FA/P

Logic

TM

BP

PI-7695-081915

+

Start Remote

OSSP

Remote OSSP

Completed

No

Yes

5 V Output

Present?

Set D+ to High

Impedance

CHY103 Detected

System Fault and

Shutdown Adapter

Reduce Load

Current to <50 mA

CHY103 Initiates

System Level Fault

Monitor

Wait Minimum

40 ms

PI-7697-081915

Initiate USB BC 1.2

and QC 3.0

Handshake

System Fault

Notification