34701_07 Datasheet, PDF (12/38 Pages) Freescale Semiconductor, Inc – 1.5 A Switch-Mode Power Supply with Linear Regulator

ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
Table 4. DYNAMIC ELECTRICAL CHARACTERISTICS
Characteristics noted under conditions -40°C ≤ T_A ≤ 85°C unless otherwise noted. Input voltages VIN1 = VIN2 = 3.3 V using
the typical application circuit (see Figures 33) unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
BUCK CONVERTER
Duty Cycle Range (Normal Operation) ⁽¹⁸⁾
Switching Node SW Rise Time ⁽¹⁸⁾
VIN = 5.0 V, ILOAD = 1.0 A
t_D
t_RISE
0
–
95
%
ns
–
7.0
–
Switching Node SW Fall Time ⁽¹⁸⁾
VIN = 5.0 V, ILOAD = 1.0 A
t_FALL
ns
–
17
–
Maximum Deadtime ⁽¹⁸⁾
t_D
Buck Control Loop Propagation Delay ⁽¹⁸⁾
t_PD
VINV < 0.8 V to VSW > 90% of High Level or VINV > 0.8 V to VSW < 10%
of Low Level
–
35
–
ns
ns
–
50
–
Soft Start Duration (Power Sequencing Disabled, EN1 = 1, EN2 = 1) ⁽¹⁸⁾
t_SS
200
350
800
µs
Fault Condition Time-Out ⁽¹⁸⁾
t_FAULT
7.0
10
15
ms
Retry Timer Cycle ⁽¹⁸⁾
t_RET
70
100
150
ms
OSCILLATOR
Oscillator Center Frequency⁽²⁰⁾
RF = 11.3 kΩ
f_OSC
270
300
330
kHz
Oscillator Frequency Range
Oscillator Frequency Adjusting Resistor Range
Oscillator Frequency Adjustment ^{(19), (20)}
RF = 7.0 kΩ
Oscillator Frequency Adjustment ^{(19), (20)}
RF = 22 kΩ
f_OSC
200
–
400
kHz
R_FREQ
7.0
–
22
kΩ
f_OSC
400
–
kHz
–
f_OSC
kHz
–
–
200
Oscillator Default Frequency (Switching Frequency), FREQ Pin Open
Oscillator Output Signal Duty Cycle (Square Wave, 180° Out-of-Phase with
the Internal Suitable Oscillator)
Synchronization Pulse Minimum Duration ⁽¹⁸⁾
Notes
18. Design information only. This parameter is not production tested.
19. see Figure 4 for more details
20. RF is RFREQ
f_OSC
D_OSC
t_SYNC
–
300
40
50
1.0
–
–
kHz
%
60
–
µs
34701
12
Analog Integrated Circuit Device Data
Freescale Semiconductor