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发表于 2023-4-3 18:30:57
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Switch mode regulators
4 _, t& R+ O) y* Q& FQCC3040 VFBGA contains two switch mode regulators for optimum power efficiency. These switch mode regulators& A* J4 ]! M% E( I& B1 K) G# r# m
receive power from VBAT or VCHG under application software control.
+ c+ ]# P7 l/ S4 K K( Y7 f9 i+ e3 y7 hThe System SMPS generates the main 1.8 V supply rail, which supplies most of the analog circuits on QCC3040
% ]; P' q6 I% g% PVFBGA and the flash memory. The System SMPS can supply power to external components.# `4 d* `- d6 O1 L
The digital SMPS generates the power for the digital circuits. It is variable voltage and automatically switches$ e* {5 [7 N0 b! q; @/ _
between 1.1 V (nominal) and 0.85 V (nominal) in low-power modes.
5 w/ }' J) \7 ]) u0 gThe SMPS both have three operating modes:: Z5 e- p5 `& K# h4 ~4 L
■ Normal (PWM)' Q+ [& ?& J2 t) m
■ Two low-power modes with reduced current capability:
' P* ?5 u6 I5 O. e8 U5 c2 O- s□ PFM& X2 f6 Q& h" U( g: I! p
□ ULP1 n/ G1 K) }7 A9 E5 P
Normally the system auto switches, but this is optionally disabled.! c1 X7 ` o" w: ^# \/ y' @
The SMPS uses a 4.7 μH inductor and a 4.7 μF output capacitor.7 Y( ?+ b: N0 Y/ k8 B3 q7 _
For guidance on choice of inductor, capacitor and layout, see QCC3040 VFBGA Hardware Design Guide (80-
- X' t9 `/ T; t% `# H7 p, ~9 JCH285-1).7 B0 d" w) U. c; d& V" o
A single node SMPS_DCPL is a low impedance decoupling point for the inputs to both SMPS. This point must have( d: Y- C f' q+ l. j) L
a 2.2 μF. QTIL recommends using a 100 nF capacitor on the SMPS_DCPL point.
% x9 y; g1 s9 O5 [8 dThe SMPS Regulators are enabled by a rising edge on SYS_CTRL, or a rising edge on VBAT or presence of VCHG.
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