RN5T614 PCB LAYOUT GUIDE - Ricoh

RN5T614 PCB LAYOUT GUIDE
RN5T614
PCB Layout Guide
Version 1.1
September 28, 2012
RICOH COMPANY, LTD.
Electronic Devices Company
©2012

RN5T614 PCB LAYOUT GUIDE
Abstract
This document describes the constraints and points when designing the PCB layout with RN5T614.
This guide provides examples to explain of how it can be done.
The PCB layout example is helpful to achieve optimal RN5T614 performance.
Contents
1. Basic Policy and Examples of Board Pattern ............................................................................................. 3
1.1 .................................................................................................................................... 3
1.2 .................................................................................................................................. 6
2. Recommended External Parts List ............................................................................................................. 7
3. Example of Parts Layout............................................................................................................................. 8
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RN5T614 PCB LAYOUT GUIDE
1. Basic Policy and Examples of Board Pattern
1.1
Current Loop
Cin_A
Analog
Power
Supply
RN5T614
Buffer
Power
Supply
Cin_B
(Input capacitance)
VFB
Control
and
Analog
BUF
LX
L
Vout
Cout
(Output capacitance)
Analog
GND
Buffer
GND
Fig. 1-1: Simplified Schematic for DCDC1 and DCDC2
Analog
Power
Supply
RN5T614
Buffer
Power
Supply
Current Loop
Cin_A
Cin_B
(Input capacitance)
Control
and
Analog
BUF
LX
R1
L
Cf
Vout
Cout
(Output capacitance)
+
- VREF
VFB
R2
Analog
GND
Buffer
GND
Fig. 1-2: Simplified Schematic for DCDC3
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RN5T614 PCB LAYOUT GUIDE
RN5T614 Pin Names
DCDC1 DCDC2 DCDC3
Analog Power Supply
VINA
Buffer Power Supply VINP1 VINP2 VINP3
VFB VFB1 VFB2 VFB3
LX LX1 LX2 LX3
Table 1-1: RN5T614 Pin Names
(7)
(8)
(3)
C
L
(1)
(4)
(5)
(6)
(5)
(1)
(4)
LX
L
C
VOUT
(2)
(7)
(3)
Fig. 1-3: DCDC Block Evaluation Board Pattern (Top Layer)
(1) Place the parts to minimize the switching current loop (Figure 1-1 and 1-2: blue line, Figure 1-3: red
line).
(2) Route the LX line between RN5T614 and an inductor as short and wide as possible,
and yet should not add other redundant lines on it
(3) Connect the GND line of “Cout” directly to the internal GND plane with multiple vias, in order to reduce
impedance as small as possible. (Target: 50mΩ or less)
(4) Begin to route the VOUT line from near not “L” but “Cout”.
(5) Place “Cin” as close as possible to RN5T614. (Higher priority level is “Cin” < L < “Cout” in the close
distance order with RN5T614.)
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RN5T614 PCB LAYOUT GUIDE
(7)
VFB3
VFB1
(7)
Fig. 1-4: DCDC Block Evaluation Board Pattern
*Top Layer (High-light: Lx and VOUT) + 3rd Layer (VFB)
(6) Place inductors for DCDC1, DCDC2 and DCDC3 without becoming too close between them, in order to
avoid the electromagnetic interference.
(7) Route the VFB line not to go back into the chip parallel to noise source as the LX line in the same layer,
and it's preferable to set the VFB line in the different layer from noise source.
In addition, it should not pass under the Inductors.
(8) Place R1, R2, and Cf as close as possible in the same layer, and connect GND of R2 to Cout's in
DCDC3.
Note:
*Need to arrange the layout pattern of DCDC2 along with DCDC1's, too. (Pay attention to (6) at that time.)
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RN5T614 PCB LAYOUT GUIDE
1.2
IMONI
(1)
VCHG
VBAT
VSYS
(2)
Fig. 1-5: Charger Block Evaluation Board Pattern (Top Layer)
(1) Place each capacitor (VCHG, VSYS*, VBAT*) as close as possible to RN5T614 and route the line to
RN5T614 short and widely in order to minimize resistance.
(2) Place IMONI resistance as close as possible to RN5T614 and route the line of it to avoid the having
many parasitic resistance. And Use the high-accuracy resistance (Recommended value: ±0.5% or less)
in order to increase the accuracy of Charge Current.
(3) The device can withstand up to 6.5V on VCHG pin. However, it can withstand high voltage by combining a
high voltage protection IC (up to 28V by using BD6040 of ROHM)
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RN5T614 PCB LAYOUT GUIDE
2. Recommended External Parts List
RN5T614 External Parts
Block Pin Name
Parts Size [mm]
Parts
Model value Vender Num
X Size Y Size Z Size [mm2]
PMU - - RN5T614 RICOH 1 6.00 6.00 0.90 36
CHG VCHG 4.7uF GRM21BB31E475KA75B Murata 1 2.00 1.25 1.25 2.5
Zener Diode RD6.8UM RENESAS 1 2.10 0.80 0.70 1.68
(for OVP) OVP BD6040 ROHM 1 1.60 1.60 0.55 2.56
2.2uF GRM188B31C225KE14B Murata 1 1.60 0.80 0.80 1.28
VSYS1 10uF C1608JB0J106M TDK 1 1.60 0.80 0.80 1.28
VSYS2
VSYS3
VBAT1 4.7uF GRM188B30J475KE18B Murata 1 1.60 0.80 0.80 1.28
VBAT2
THERMBAT Thermistor NTCG103JF103GT TDK 1 1.00 0.50 0.50 0.5
10kohm - 1 1.00 0.50 0.35 0.5
VTHM 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
IMONI 1kohm 1kohm +/- 0.5% - 1 1.00 0.50 0.35 0.5
VCHGREG 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
DCDC VINA 2.2uF LMK107BJ225KA Taiyo Yuden 1 1.60 0.80 0.80 1.28
VINP1 2.2uF LMK107BJ225KA Taiyo Yuden 1 1.60 0.80 0.80 1.28
LX1 2.2uH NRH2410T2R2MN Taiyo Yuden 1 2.40 2.40 1.00 5.76
VFB1 10uF C1608JB0J106M TDK 1 1.60 0.80 0.80 1.28
VINP2 10uF LMK107BBJ106MALT Taiyo Yuden 1 1.60 0.80 0.80 1.28
LX2 2.2uH NRH2410T2R2MN Taiyo Yuden 1 2.40 2.40 1.00 5.76
VFB2 10uF C1608JB0J106M TDK 1 1.60 0.80 0.80 1.28
VINP3 2.2uF LMK107BJ225KA Taiyo Yuden 1 1.60 0.80 0.80 1.28
LX3 2.2uH MLP2012S2R2M TDK 1 2.00 1.25 1.00 2.5
VFB3 4.7uF C1608JB1A475K TDK 1 1.60 0.80 0.80 1.28
R1 (for DCDC3 Voltage set) - 1 1.00 0.50 0.35 0.5
R2 (for DCDC3 Voltage set) - 1 1.00 0.50 0.35 0.5
Cf (for DCDC3 Voltage set) - 1 1.00 0.50 0.50 0.5
LDO VIN1 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VREF 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT1 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT2 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT3 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT4 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUTD 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VIN2 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT5 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT6 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VIN3 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT7 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
VOUT8 1.0uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
OTHER VDDIO 0.1uF GRM155B31A105KE15 Murata 1 1.00 0.50 0.50 0.5
BATDET 330kohm for Pullup - 1 1.00 0.50 0.35 0.5
ONOB 330kohm for Pullup - 1 1.00 0.50 0.35 0.5
RESETO 330kohm for Pullup - 1 1.00 0.50 0.35 0.5
SDA 330kohm for Pullup - 1 1.00 0.50 0.35 0.5
INTB 330kohm for Pullup - 1 1.00 0.50 0.35 0.5
Total Num 44 Total Parts size 83.06
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RN5T614 PCB LAYOUT GUIDE
3. Example of Parts Layout
8.1 mm
4.5 mm
R
2.3 mm
C
C
R
C
C
R
R
C
R
R
L
C
C
8.5 mm
3.2 mm
C
BD60
40
GUL
D
C
C
C
RN5T614
C
L
C
11.6 mm
10.5 mm
C C
C
C
C
C
C
L
C
R
R
R
C
C
C
C
C
C
C
1.6 mm
Total Parts Area 158.21mm 2
Fig. 3-1: Example PCB Parts Layout
Note: Connect Exposed Paddle (Tab on the bottom side) to GND.
©2012 Page 8