LM3753 Datasheet, PDF (9/38 Pages) National Semiconductor (TI) – Scalable 2-Phase Synchronous Buck Controllers with Integrated FET Drivers and Linear Regulator Controller

Symbol Parameter
Conditions
PH_RATIO
V_PH/V_VCC Divider Ratio to Set
Phase Number
2 & 4 Phases
3 Phases
5 Phases
6 Phases
8 Phases
10 Phases
12 Phases
I_PH
Φ_HG1-N2
PH Bias Current
V_VCC = 4.5V forced, V_PH = 0 to V_VCC
HG1 to HG2 Phase Shift for 2, 4, 6,
8, 10 or 12-Phase Modes
Φ_HG1-N3
HG1 to HG2 Phase Shift for 3-
Phase Mode
Φ_HG1-N5
HG1 to HG2 Phase Shift for 5-
Phase Mode
Φ_SYNC
SYNC to SYNCOUT Phase Shift N > 2
for N-phase Operation
N=2
t_SYNC-ERR
SYNC to SYNCOUT Phase Shift
Error
t_SYNC-HG
Φ_HG-ERR
SYNC to HG1(2)
HG1 and HG2 Controller-to-
Controller Phase Delay Error
300 kHz, 6-phase
Soft-Start (LM3754): SS, Pre-Biased Startup
I_SS
R_DS-SS
t_LG-PW1
SS Source Current
Soft-Start Pull-Down Resistance
First LG High Pulse Width during
Soft-Start
V_SS = 0.3V
t_LG-GT
LG Asynchronous-to-Synchronous
Gradual Transition Time
t_D-EN-SW EN-to-Switching Delay
Delay from EN = High to FAULT = High; no
pre-bias
Tracking (LM3753): TRACK
V_TRACK
V_HYS-TRACK
t_SS-INT
Tracking Range
TRACK Falling Voltage Hysteresis
Internal SS Time during Fault
Recovery
After Fault
I_TRACK
t_LG-PW1
TRACK Input Bias Current
V_TRACK = 0.3V
V_TRACK = 5V
First LG = High Pulse Width during
Fault Recovery
t_LG-GTF
LG Asynchronous-to-Synchronous
Gradual Transition Time during
Fault Recovery
t_D-EN-SW EN-to-Switching Delay
Delay from EN = High to FAULT = High; no
pre-bias; V_TRACK = 0.6V
Min
0.152
0.294
0.438
0.587
0.730
0.874
−150
5.7
0
Typ
0
3/14
5/14
7/14
9/14
11/14
1
180
240
216
360/N
90
5
165
5
10
750
460
2
2
50
3.8
5
0.2
460
1.8
2
Max
0.138
0.279
0.418
0.562
0.703
0.844
Units
150
nA
°
°
°
°
ns
ns
°
14.6 µA
Ohm
ns
ms
ms
V_REF
V
mV
ms
200
nA
mA
ns
ms
ms
9
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