TLE 8366EV Infineon Technologies, TLE 8366EV Datasheet - Page 7

• Manufacturer Part Number: TLE 8366EV
• Manufacturer: Infineon Technologies

Specifications of TLE 8366EV

• Packages: PG-DSO-8
• Comment: VQ adjustable from 0.6V up to 16V; Tolerance 2% up to 1000mA; DSO-8 EP
• Vq (max): adjustable
• Iq (max): 1,800.0 mA
• Iq (typ): 7,000.0 µA
• Output: Buck Converter

5
5.1
5.1.1
The step-down (or buck) regulator consists of several functional blocks, which shall be explained in the following:
The oscillator, the regulator, the safety functions, the gate driver and the internal MOSFET.
5.1.1.1
The oscillator creates a saw-tooth signal, which is supplied to the PWM comparator and the Schmitt-Trigger 1. The
frequency of the oscillator might be synchronized to an external frequency connected to pin sync.
The Error Amplifier compares the feedback signal to the reference voltage. At the variable voltage version the
feedback pin shall be connected to an external resistor divider, the fixed voltage versions contain an internal
resistor divider. The soft start function is included by the ramp generator between the reference voltage source
and the error amplifier. It generates a defined ramp after the initialization of the device. (The device is initialized
after signal EN turns to high (with supply voltage at VS present) or with rising Supply voltage (with EN = H
connected to VS) or at restarting after a thermal shutdown. The ramp starts, if the Buck Driver Supply (BDS)
external capacitor is charged.
Only for the variable voltage version: If the feedback signal at pin FB gets lost, an internal pull-up current source
will pull the pin too high thus preventing the output voltage from overshooting.
A compensation network needs to be connected to the output of the error amplifier using pin COMP.
The PWM comparator creates the Pulse-Width Modulated (PWM) signal by comparing the error amplifier output
with the saw-tooth signal from the oscillator.
5.1.1.2
The safety functions block consists of the Error-Flip Flop, the Nor1 Gate and the PWM-Flip-Flop.
The Error Flip-Flop collects the failure events such as the over-current shutdown of the internal MOSFET, the
output overvoltage shutdown and the temperature shutdown.
The over-current shutdown signal is created by the OC comparator. It detects the voltage across an internal shunt
resistor. If the current exceeds the reference level, the pulse is shut down and the MOSFET switched off.
capacitor voltage to a reference level. If the bootstrap capacitor voltage is too low, the pulse will be shut down and
the MOSFET switched off.
If the output voltage exceeds a reference value, the pulse will also be shut down and the MOSFET switched off.
Data sheet
The bootstrap under-voltage shutdown is created by the BDS UV comparator, which compares the bootstrap
Buck Regulator
Description
Arrangement
Regulator Block
Safety Functions Block
7
Rev. 1.0, 2009-05-18
Buck Regulator
TLE8366