STOTG04ES datasheet(14/26 Pages) STMICROELECTRONICS

14 / 26 page

Block description

STOTG04ES

14/26

Block description

The STOTG04ES integrates a charge pump and comparators for the VBUS, ID line detector and interrupt

switch, differential data driver, differential and single-ended receivers, low dropout voltage regulator and

control logic. The STOTG04ES provides a complete solution for connection of a digital USB OTG

controller to the physical Universal Serial Bus.

6.1

Charge pump

The VBUS line voltage is provided using the internal charge pump. It is capable of sourcing up to 35mA

load current. The charge pump can be powered by voltage from 2.7V to 5.5V. It needs two capacitors for

its operation: an external capacitor of 220nF connected between the CAP1 and CAP2 pins and a 4.7µF

decoupling tank capacitor on the VBUS. In case when an application needs higher current than 35mA, it is

possible to provide it using an external charge pump or switch controlled by the ADR_PSW pin.

6.2

VBUS Comparators

These comparators monitor the VBUS voltage. They provide current status information for the VBUS line.

VBUS valid status means that the voltage is above VBUS_VLD. Session valid status means that the VBUS

voltage is above VSES_VLD level.

6.3

Voltage regulator

An internal low-dropout voltage regulator provides power supply for the bus drivers and receivers. The

regulator needs an external capacitor of 1µF on the VTRM pin for its proper operation. The regulator can

provide 3.3V or 2.75V output voltages according to the Operating Mode.

The regulator can be bypassed in case when the analog supply voltage is in the range of 3.0V (or 2.7V)

to 3.6V. It is necessary to tie the VTRM pin to the VBAT power supply voltage to bypass the regulator.

6.4

ID Line detector

This block senses ID line status. It is capable of detecting three different line states:

• pin floating;

• pin tied to ground;

• pin grounded via a 140k

Ω resistor.

The ID detector can also generate an interrupt by shorting the pin to ground.

6.5

Driver and receivers

The driver can operate in two different modes. It can act as a simple low-speed and full-speed differential

USB driver or as two independent single-ended drivers in the UART mode.

This block contains one differential receiver for the USB operation mode and two single-ended receivers

for USB signaling as well as UART receivers.

STOTG04ES Datasheet(PDF) 14 Page - STMicroelectronics