TLD5541-1QV Datasheet, PDF (26/82 Pages) Infineon Technologies AG – H-Bridge DC/DC Controller with SPI Interface

H-Bridge DC/DC Controller with SPI Interface
TLD5541-1QV
Regulator Description
V_IN
HSGD1
SWN1
M1 _{(3) Energizing}
L_OUT
LSGD1
(4) Recirculation
M2
V_OUT
M4
ON
HSGD2
SWN2
M3 ^OFF
LSGD2
I_LOUT
M1
M1
M1
t
M2+M4
+
M2+M4
+
M2+M4
+
M4
M4
M4
R_SWCS
Figure 12 4 switches H-Bridge architecture in BUCK mode
Simplified comparison of 4 switches architecture to traditional asynchronous Buck approach.
• M3 is always OFF in this mode (open).
• M4 is always ON in this mode (closed connection inductor to V_OUT).
• M2 acts as a synchronous diode, with significantly lower conduction losses (I² x R_DSON vs. 0.7V x I)
V_IN
M1
HSGD1
LSGD1
LOUT
M4
(ON)
V_OUT
M3
M2
(OFF)
HSGD2
LSGD2
M1
V_IN
HSGD1
R_SWCS
L_OUT
D1
V_OUT
a) 4 switch architecture BUCK
b) standard asynchronous BUCK
Figure 13 4 switches H-Bridge architecture in BUCK mode compared to standard async BUCK
6.4.3
Buck-Boost mode (V_IN ~ V_OUT)
• When V_IN is close to V_OUT the controller is in Buck-Boost operation.
• All switches are switching in buck-boost operation. The direct energy transfer from the Input to the output
(M1+M4 = ON) is beneficial to reduce ripple current and improves the energy efficiency of the Buck-Boost
control scheme.
• The two buck boost waveforms and switching behaviors are displayed in Figure 14 below.
Data Sheet
26
Rev. 1.0, 2016-05-20