TLE6389 Datasheet, PDF (16/23 Pages) Infineon Technologies AG – Step-Down DC/DC Controller

TLE 6389
4
Detailed Description
The TLE6389 family is a family of step-down DC-DC controllers designed primarily for
use in high voltage applications such as automotive. Using an external MOSFET and
current-sense resistor allows design flexibility and the improved efficiencies associated
with high-performance P-channel MOSFETs. A unique, current-limited, pulse-width
(PWM)/pulse-frequency-modulated (PFM) control scheme gives these devices excellent
efficiency over load ranges up to three decades, while drawing less than 100µA under
no load. This wide dynamic range optimizes the TLE6389 for automotive applications,
where load currents can vary considerably as individual circuit blocks are turned on and
off to conserve energy. Operation to a 100% duty cycle allows the lowest possible
dropout voltage, allowing operation during cold cranking. High switching frequencies and
a simple circuit topology minimize PC board area and component costs.
The output voltage is sensed either by an internal voltage divider connected to the FB
pin (TLE6389-50 and TLE6389-33) or an external divider returned to the FB pin
(TLE6389).
R_SENSE=
V_IN
0.05

M1
L₁ = 47 µH
V_OUT
I_OUT
C_IN1 =
100 µF
C_BDS=
220 nF
C_OUT =
D1
100 µF
R_SI1=
400k

R_SI2=
100k

11
13 ^BDS
C_IN2 =
VS
220nF ₇
SI
14
CS
12
GDRV
TLE6389G50
2
FB
3
VOUT
9
SO
10
RO
M1: Infineon SPD09P06PL
D1: Motorola MBRD360
L1: Coilcraft DO3340P-473
Cin1: TBD
Cout: Low ESR Tantalum
SI_GND ENABLE SYNC GND RD
6
1
54
8
ON OFF
C_RD =100nF
TLE6389G50 Application Circuit
Target Datasheet Rev. 1.7
16
2001-09-17