UCHQ613

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

8 of 9

www.unisonic.com.tw

QW-R121-030.a



FUNCTIONAL DESCRIPTION (Cont.)

Applying 1.2 V to the D+ Line and 1.2 V to the D– Line

As shown in Figure 4, some tablet USB chargers require 1.2 V on the shorted data lines of the USB connector.The

maximum resistance between the D+ line and the D- line is 200 Ω.

The UTC UCHQ613 are USB dedicated charging port (DCP) controllers. Applications include vehicle power

charger, wall adapters with USB DCP and other USB chargers. The UTC UCHQ613 DCP controllers have the

auto-detect feature that monitors the D+ and D– line voltages of the USB connector, providing the correct electrical

signatures on the DP and DM pins for the correct detections of compliant portable devices to fast charge. These

portable devices include smart phones, 5-V tablets and personal media players.

DCP Auto-Detect

The UTC UCHQ613 integrate an auto-detect feature to support divider mode, short mode and 1.2 V / 1.2V modes.

If a divider device is attached, 2.7 V is applied to the DP pin and 2 V is applied to the DM pin. If a BC1.2-compliant

device is attached, the UTC UCHQ613 automatically switches into short mode. If a device compliant with the 1.2 V /

1.2 V charging scheme is attached, 1.2 V is applied on both the DP pin and the DM pin. The functional diagram of

DCP auto-detect feature (DM1 and DP1) is shown in Figure 5. DCP autodetect feature (DM2 and DP2 of UCHQ613)

has the same functional configuration.

GND

D-

D+

5 V

1.2 V

K1

K2

K3

K4

2.0 V

2.7 V

Divider 2

K1,K3:ON

K2,K4:OFF

Short Mode

K4:ON

K1,K2,K3:OFF

1.2V on DP1 and DM1

K2,K4:ON

K1,K3:OFF

Undervoltage Lockout (UVLO)

The undervoltage lockout (UVLO) circuit disables DP1, DM1, DP2 and DM2 output voltage until the input

voltage reaches the UVLO turn-on threshold. Built-in hysteresis prevents unwanted oscillations due to input voltage

drop from large current surges.