stusbcd01b STMicroelectronics, stusbcd01b Datasheet - Page 5

• Manufacturer Part Number: stusbcd01b
• Description: Usb Charger Detection Interface
• Manufacturer: STMicroelectronics

3
3.1
3.2
3.3
Functional description
The STUSBCD01B is designed to provide USB charger detection functionality to USB
platforms which do not have this feature integrated in the PHY. The device can work with a
supply voltage ranging from 2.2 V to 4.5 V and has an internal regulator which generates the
1.8 V voltage required for the internal blocks and state machine.
The STUSBCD01B can detect a dedicated charger or a Host/Hub charger connected to
USB data lines and
output signal. The open drain output can be disabled using the /OE input signal.
Two different detection methods, selectable through the STATUS/METHOD pin, are
implemented in order to distinguish between a dedicated charger and a Host/Hub charger. If
the interface voltage is not present the detection method is defined by the status of default
method pin.
The STUSBCD01B features very low power consumption in Standby mode and low input
capacitance on DP/DM pins. An over voltage protection circuit is also implemented on the
VBUS pin in order to limit V
connected to it.
Detection methods
The STUSBCD01B implements a current source/sink method to detect dedicated chargers
(wall chargers) and a current sink method for Host/Hub chargers (based on USB battery
charging spec v1.0). If a standard Host/Hub is connected to the device it is recognized
thanks to its pull-down resistors on DP/DM lines and therefore DETECT/STATUS outputs
will be low.
Dedicated charger detection method
Selected driving method pin low during the falling edge of shutdown or driving default
method pin low if V
source on DP pin and a current sink on DM pin to detect the resistor (max 200 Ω) which
connects DP and DM in dedicated chargers.
Current sink method
Selected driving method pin high during the falling edge of shutdown or driving default
method pin high if V
and a current of IDAT_SINK is drawn from DM.
If a Host/Hub charger is connected, STUSBCD01B will see a voltage of VDAT_SRC on pin
DM. The same happens if a dedicated charger is connected and, therefore, in order to
distinguish between the two, if the current sink method detection is successful it is
necessary to run the dedicated charger detection method immediately after.
IO
IO
is not present. The dedicated charger detection method uses a current
provides both an open drain pin and a digital I/O pin for the detection
is not present. A voltage source of VDAT_SRC is connected to DP
BUS
voltage to 6 V and provide protection to external devices
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