Datasheet

D+
D-
VDP_SRC
VLGC_HI
IDP_SRC
CHG_DET
VDAC_REF
IDM_SINK
RDM_DWN
bq24190, bq24192
bq24192I, bq24193
SLUSAW5A –JANUARY 2012–REVISED OCTOBER 2012 www.ti.com
Figure 25. USB D+/D- Detection
DCD (Data Contact Detection) uses a current source to detect when the D+/D– pins have made contact during
an attach event. The protocol for data contact detect is as follows:
• Detect VBUS present and REG08[2]=1 (power good)
• Turn on D+ I
DP_SRC
and the D– pull-down resistor R
DM_DWN
for 40ms
• If the USB connector is properly attached, the D+ line goes from HIGH to LOW, wait up to 0.5 sec.
• Turn off I
DP_SRC
and disconnect R
DM_DWN
The primary detection is used to distinguish between USB host (Standard Down Stream Port, or SDP) and
different type of charging ports (Charging Down Stream Port, or CDP, and Dedicated Charging Port, or DCP).
The protocol for primary detection is as follows:
• Turn on V
DP_SRC
on D+ and I
DM_SINK
on D– for 40ms
• If PD is attached to a USB host (SDP), the D– is low. If PD is attached to a charging port (CDP or DCP), the
D– is high
• Turn off V
DP_SRC
and I
DM_SINK
Table 2 shows the input current limit setting after D+/D– detection.
Table 2. bq24190 USB D+/D– Detection
D+/D– DETECTION OTG INPUT CURRENT LIMIT REG08[7:6]
0.5 sec timer expired in DCD — 100 mA 00
(D+/D- floating)
USB Host LOW 100 mA 01
USB Host HIGH 500 mA 01
Charging Port — 1.5 A 10
PSEL/OTG Pins Set Input Current Limit in bq24192, bq24192I, bq24193
The bq24192, bq24192I, bq24193 has PSEL instead of D+/D–. It directly takes the USB PHY device output to
decide whether the input is USB host or charging port.
Table 3. bq24192, bq24192I, bq24193 Input Current Limit Detection
PSEL OTG INPUT CURRENT LIMIT REG08[7:6]
HIGH LOW 100 mA 01
HIGH HIGH 500 mA 01
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Product Folder Links: bq24190 bq24192 bq24192I bq24193