TLE 7368E Infineon Technologies, TLE 7368E Datasheet - Page 36

• Manufacturer Part Number: TLE 7368E
• Manufacturer: Infineon Technologies

Specifications of TLE 7368E

• Packages: PG-DSO-36
• Comment: 3 linear post regulators (5V, 3.3/2.6V, 1.5V),selectable StandBy-Vreg (1.0/2.6V) and 2 voltage trackers (5V)
• Vq (max): 5.0 V, 3.3/2.6 V, 1.5 V, 1.0/2.6 V
• Iq (max): 2,500.0 mA
• Iq (typ): 120.0 µA
• Output: Linear (Buck Preregulator)

This section intends to give hints for correct set up of the IC, i.e. to avoid misbehavior caused by the influence of
other PCB board circuits and shows also how to calculate external components, power loss, etc.
6.1
Stable operation of the Buck converter is ensured when choosing the external passive components according to
the characteristics given below:
•
•
•
6.2
The linear regulators LDO1 and LDO2 need to be connected to appropriate output capacitors in order to keep the
regulation loop stable and avoid oscillations. The essential parameters of the output capacitor are the minimum
capacitance and the equivalent series resistance (ESR). The required ranges for each output are specified in
Chapter 4.4 (Electrical
suitable for LDO1 and LDO2.
Table 1
No.
1
2
6.3
LDO3 consists of an integrated regulator which needs to be equipped with an external power transistor (NPN-
Type). Suitable NPN power transistors types are e.g. KSH 200 from Fairchild semiconductor or NJD 2873T4 from
ON semiconductor. The most important parameters to be checked when choosing the external transistor are the
‘current gain bandwidth product’ (
Darlington type transistors should not be used. For stability of the regulation loop a multi layer ceramic capacitor
of min. 4.7 F must be connected to the LDO3 output voltage (Emitter of the external power transistor). In order
to improve suppression load current steps an additional capacitor of tantalum type can be connected in parallel.
In case LDO3 voltage is not needed the external NPN transistor can be spared. For this configuration the pins
‘DRV_EXT’ and ‘FB_EXT’ should be directly connected to each other in order to ensure correct operation of
Reset 2. Also in this case a small ceramic capacitor of 220 nF connected from pin ‘FB_EXT’ to GND is
recommended in order to avoid oscillations of the regulation loop LDO3.
Data Sheet
Buck inductance: 18 H <
Buck output capacitor:
ESR of Buck output capacitor: ESR_
SEL_LDO2
GND
Q_LDO2
Choosing Components for the Buck Regulator
Setting up LDO1, LDO2
LDO2 Output Voltage Configuration
Setting up of LDO3
Characteristics). Tantalum capacitors as well as multi layer ceramic capacitors are
C
Buck
L
Buck
> 20 F
f
< 220 H
T
), the ‘DC current gain’ (h
C
Buck
< 150 m
36
Q_LDO2
2.6 V
3.3 V
FE
) and the thermal resistance of the package.
Application Information
Rev. 2.1, 2010-11-22
TLE7368