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发表于 2023-4-3 18:30:57
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Switch mode regulators$ n; R5 c; y7 z$ T. s2 a
QCC3040 VFBGA contains two switch mode regulators for optimum power efficiency. These switch mode regulators6 q& n2 j5 q( J! N0 S: z0 w' o% k
receive power from VBAT or VCHG under application software control.
' Y" B& m" P5 r' TThe System SMPS generates the main 1.8 V supply rail, which supplies most of the analog circuits on QCC3040& o- K/ E" H4 x7 M6 d0 i$ E
VFBGA and the flash memory. The System SMPS can supply power to external components.! s- v- F- U( l6 G8 u: a" c% T! X Y
The digital SMPS generates the power for the digital circuits. It is variable voltage and automatically switches7 `- s" J* W& @4 A
between 1.1 V (nominal) and 0.85 V (nominal) in low-power modes." r" }6 x7 L" m, G7 J$ Z! Y
The SMPS both have three operating modes:
$ Z& k, {9 P; T! }2 B■ Normal (PWM)+ M" {: v" S2 U
■ Two low-power modes with reduced current capability:, Y4 @/ P5 l& b3 z- B0 L+ A! j0 @
□ PFM& S" O: u A5 u) V; x
□ ULP
7 x6 h- P7 O1 v$ L; B' \ l; g$ QNormally the system auto switches, but this is optionally disabled.) ], W _7 k5 @! S
The SMPS uses a 4.7 μH inductor and a 4.7 μF output capacitor.
1 O& i( E }! C3 }# Y) O+ LFor guidance on choice of inductor, capacitor and layout, see QCC3040 VFBGA Hardware Design Guide (80- ]9 k8 l+ l4 W, z3 {! q0 i) H. G
CH285-1).
) d q/ a3 C8 b9 r) C- g0 K4 {! {A single node SMPS_DCPL is a low impedance decoupling point for the inputs to both SMPS. This point must have+ I \/ G" t; f0 I6 K
a 2.2 μF. QTIL recommends using a 100 nF capacitor on the SMPS_DCPL point.
. r5 ]8 Q1 w4 ]5 h- K6 F9 R- n2 RThe 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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