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发表于 2023-4-3 18:30:57
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Switch mode regulators
- }( O p7 K9 Q5 Y; d: R5 ?QCC3040 VFBGA contains two switch mode regulators for optimum power efficiency. These switch mode regulators
# A1 P2 Y0 U% f) Preceive power from VBAT or VCHG under application software control.6 k% E& K# X7 K- e( r$ d
The System SMPS generates the main 1.8 V supply rail, which supplies most of the analog circuits on QCC30402 a! U5 @; s* Y1 W4 e0 w9 x+ V' n; s9 _ \
VFBGA and the flash memory. The System SMPS can supply power to external components., [1 R: ^7 G5 r( T
The digital SMPS generates the power for the digital circuits. It is variable voltage and automatically switches/ E- y2 o: ?* E* @- U* W9 I
between 1.1 V (nominal) and 0.85 V (nominal) in low-power modes.' c# @5 n/ \+ p6 I3 p3 ?
The SMPS both have three operating modes:
/ f) j/ z' P; i/ f" Q■ Normal (PWM), X. U) Q! j! E- a
■ Two low-power modes with reduced current capability:
; f+ u- U9 y1 y; j% ?1 q$ ]! V+ u□ PFM
8 V& Z( b6 j# R1 y, i, c O) I□ ULP& G( r, D" Y' R: T
Normally the system auto switches, but this is optionally disabled.
" G _7 W2 H! y/ O. a8 |7 dThe SMPS uses a 4.7 μH inductor and a 4.7 μF output capacitor.
5 J- [9 X+ @5 W) t$ WFor guidance on choice of inductor, capacitor and layout, see QCC3040 VFBGA Hardware Design Guide (80-
6 a- D" K. i" s2 f; \/ hCH285-1).' q2 \& |$ p& S- [/ s, J- Z: R% Y: U
A single node SMPS_DCPL is a low impedance decoupling point for the inputs to both SMPS. This point must have$ `+ \8 g. g% E2 Y) ~3 q! \1 |3 T3 n
a 2.2 μF. QTIL recommends using a 100 nF capacitor on the SMPS_DCPL point.
6 @0 y( a/ D. |' [# p% L$ uThe 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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