CSR8615A04-IQQF-R View Datasheet(PDF) - Unspecified
Part Name
Description
MFG CO.
'CSR8615A04-IQQF-R' PDF : 114 Pages View PDF
C1
2.2µF
VBAT
3V3_USB
C2
2.2µF
LX
1.35V Switch-
mode Regulator
SENSE
LX_1V35
SMPS_1V35_SENSE
VSS_SMPS_1V35
6, 2013 LX
1 1.8V Switch-mode
r Regulator
mbe SENSE
LX_1V8
SMPS_1V8_SENSE
VSS_SMPS_1V8
L1
4.7µH
1.8V Supply Rail
C3
2.2µF
nday, Septe Figure 10.5: 1.8V and 1.35V Switch-mode Regulators Outputs Parallel Configuration
- Mo Minimise the series resistance of the tracks between the regulator input VBAT and 3V3_USB, ground terminals, the
.cn filter and decoupling components, and the external voltage source to maintain high-efficiency power conversion and
m low supply ripple.
.co Ensure a solid ground plane between C1, C2, C3, VSS_SMPS_1V8 and VSS_SMPS_1V35.
mm Also minimise the collective parasitic capacitance on the track between LX_1V8, LX_1V35 and the inductor L1, to
co maximise efficiency.
ache For the regulator to meet the specifications in Section 13.3.1.2 requires a total resistance of <1.0Ω (<0.5Ω
ap recommended) for the following:
- â– The track between the battery and VBAT.
sao â– The track between LX_1V8, LX_1V35 and the inductor.
T â– The inductor L1, ESR.
es â– The track between the inductor, L1, and the sense point on the 1.80V supply rail.
jam The following enable the 1.80V switch-mode regulator:
for â– VREGENABLE pin
d â– The CSR8615 QFN firmware with reference to PSKEY_PSU_ENABLES
are â– VCHG pin
Prep The switching frequency is adjustable by setting an offset from 4.00MHz using PSKEY_SMPS_FREQ_OFFSET.
When the 1.80V switch-mode regulator is not required, leave unconnected:
â– The regulator input VBAT and 3V3_USB
â– The regulator output LX_1V8
10.4 Bypass LDO Linear Regulator
The integrated bypass LDO linear regulator is available as a 3.30V supply rail and is an alternative supply rail to the
battery supply. This is especially useful when the battery has no charge and the CSR8615 QFN needs to power up.
The input voltage should be between 4.25V to 6.50V.
Note:
The integrated bypass LDO linear regulator can operate down to 3.1V with a reduced performance.
Pre-production Information
© Cambridge Silicon Radio Limited 2013
Confidential Information - This Material is Subject to CSR's Non-disclosure Agreement
Page 66 of 114
CS-303726-DSP3
www.csr.com
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