BCM43907 Preliminary Data Sheet
Internal Regulator Electrical Specifications
Section 15: Internal Regulator Electrical
Specifications
Core Buck Switching Regulator
Note: Values in this data sheet are design goals and are subject to change based on device
characterization results.
Note: Functional operation is not guaranteed outside of the specification limits provided in this section.
Table 32: Core Buck Switching Regulator (CBUCK) Specifications
Specification
Notes
Min. Typ. Max. Unit
a
Input supply voltage (DC)
DC voltage range inclusive of disturbances.
3.0
3.6
V
4.8
–
PWM mode switching frequency CCM, load > 100 mA VBAT = 3.6V.
–
–
–
4
MHz
PWM output current
Output current limit
Output voltage range
–
–
–
550 mA
1400
–
mA
V
Programmable, 30 mV steps. Default = 1.35V. 1.2
1.35 1.5
PWM output voltage DC accuracy Includes load and line regulation. Forced PWM –4
mode.
–
4
%
PWM ripple voltage, static
Measure with 20 MHz bandwidth limit.
–
7
20
mVpp
Static load. Max. ripple based on VBAT = 3.6V,
Vout = 1.35V, Fsw = 4 MHz,
2.2 μH inductor with min. effective L > 1.05 μH,
cap. + board total – ESR < 20 mΩ,
C
> 1.9 μF, ESL<200 pH
out
PWM mode peak efficiency
PFM mode efficiency
Peak efficiency at 200 mA load.
10 mA load current.
78
70
–
86
–
–
%
%
81
Start-up time from power down
VIO already ON and steady. Time from
400
500 µs
REG_ON rising edge to CLDO reaching 1.2V.
External inductor
0806 size, 2.2 µH, DCR = 0.11Ω,
ACR = 1.18Ω @ 4 MHz.
–
2.2
4.7
4.7
–
–
µH
µF
µF
µs
b
c
External output capacitor
External input capacitor
Ceramic, X5R, 0402, ESR <30 mΩ at 4 MHz,
4.7 µF ±20%, 6.3V.
2.0
10
b
For SR_VDDBAT5V pin, ceramic, X5R, 0603,
ESR < 30 mΩ at 4 MHz, ±4.7 µF ±20%, 6.3V.
–
0.67
Input supply voltage ramp-up time 0 to 4.3V.
40
–
a. The maximum continuous voltage is 4.8V. Voltages up to 6.0V for up to 10 seconds, cumulative duration, over
the lifetime of the device are allowed. Voltages as high as 5.0V for up to 250 seconds, cumulative duration, over
the lifetime of the device are allowed.
b. Minimum capacitor value refers to the residual capacitor value after taking into account the part-to-part tolerance,
DC-bias, temperature, and aging.
Broadcom®
March 12, 2016 • 43907-DS104-R
Page 91
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