AN74: SiLinkPS-EVB User's Guide

AN74
SiL INK PS-EVB U SER ’ S G UIDE
1. Introduction
The SiLinkPS-EVB is a system power supply board that
provides all the necessary supply voltages for a variety
of Silicon Laboratories’ ProSLIC and silicon DAA
evaluation boards. When used with an appropriate ac/
dc wall adapter, the SiLinkPS-EVB can provide up to
25 W of total output power. Table 1 lists some typical
voltages and currents at the power supply outputs.
Table 1. Power Supply Specifications
Input/Output
Voltage
Current
Power
VIN
9–15 V
2.5 A
22–37 W
VBRNG
–96 V
100 mA
9.6 W
VBHI
–52 V or
–78 V
100 mA
5.2 W or
7.8 W
VBLO
–26 V
200 mA
5.2 W
VDD
3.3 V/5 V
1A
3.3 W/5 W
Any combination of outputs is possible as long as the
simultaneous total power from all outputs does not
exceed the maximum rated 25 W and can be sufficiently
supported by the input power from the VIN.
The SiLinkPS-EVB is designed with the same footprint
as all ProSLIC evaluation board daughter cards
High
Voltage
Battery
Supply
allowing it to be used in conjunction with multiple
ProSLIC daughter cards to create a modular evaluation
platform.
The SiLinkPS-EVB circuit is based on two power supply
controllers from Linear Technology that provide high
efficiency and low bill-of-materials cost. Both circuits
can be synchronized to the same switching frequency to
reduce power supply switching noise. The outputs can
be configured to support both internal and external
ringing architectures by setting the provided jumpers to
set the desired output voltages. Further modifications
are possible to realize specific output voltage and
current requirements provided the total output power
does not exceed the rated maximum. Schematic
capture and layout gerber files are available for
integration into specific applications. Figure 1 illustrates
a simplified block diagram of the SiLinkPS-EVB supply
board.
2. Operating Instructions
The SiLinkPS-EVB board should always be connected
to the ProSLIC evaluation board platform prior to turning
on the power supply. Plugging any ProSLIC board into a
live high-voltage supply can permanently damage the
ProSLIC ICs. The user should exercise caution when
touching any part of the SiLinkPS-EVB because
dangerous high voltages are present and can cause
injury.
Jumper
Selection
JP2, JP3,
JP4
VBRNG
VBHI
VBLO
VDC in
VDD
Low
Voltage
VDD
Supply
JP6 VDD on/off
JP5 3.3 V/5 V Selector
Figure 1. SiLinkPS-EVB Power Supply Simplified Block Diagram
Rev. 0.2 8/03
Copyright © 2003 by Silicon Laboratories
AN74-DS02
AN74
2.1. High-Voltage Battery Supply
The schematic for this power circuit is illustrated in
Figure 3 on page 4. The LTC3704 dc-dc controller IC is
used to drive an external MOSFET and a multi-tap
transformer to create four equal high-voltage negative
outputs, VNEG (See Table 2), from the dc input supply.
Only one output is regulated via close-loop feedback.
The other three outputs are cross-regulated to the first
output via the transformer ratio. The LTC3704’s
negative feedback input eliminates inverting circuitry
when creating negative outputs from a positive input.
The six-winding 1:1 ratio transformer is configured in a
manner that minimizes the need for multiple highvoltage output filter capacitors.
JP7 jumper. The voltage on the VBHI and VBRNG
outputs can be programmed by moving the jumper
settings on JP2, JP3, and JP4. Table 2 provides several
popular configurations and the required jumper settings.
2.3. Frequency Adjustment
The LTC3704 can be configured to run at switching
frequencies from 50 kHz to 1 MHz allowing flexibility to
choose the optimal efficiency/cost point for each
specific application. Resistor R18 programs the
switching frequency according to the characteristic
curve shown in Figure 2.
1000
2.2. VNEG Voltage Adjustment
RT (kΩ)
The transformer, T1, has four secondary windings, each
producing an equal negative voltage, VNEG. These four
windings are connected in series through the diode
rectifying circuits to produce four negative voltage
potentials with voltage levels equal to multiples from 1
to 4 of the VNEG magnitude. Any adjustment made to
the VNEG has a direct effect on the voltage levels on all
negative outputs.
Resistor R23 can be modified to realize custom output
voltages as defined in the following equation.
100
10
VNEG = (1.23 x R23/R22) + 1.23
The SiLinkPS-EVB is shipped with R23 = 33.2 k and
R22 = 1.65 k for VNEG equal to 26 V.
0 100 200 300 400 500 600 700 800 900 1000
FREQUENCY (kHz)
Figure 2. Timing Resistor R18 Value
The VBLO is normally used for off-hook state and its
voltage level can be programmed by the setting on the
Table 2. Popular Application Configurations and Jumper Settings
Dual ProSLIC
Part Number
Si3211/Si3212
Si3220/Si3232
Si3225
PK-PK Ringing VBRNG
Amplitude
VBHI
VBLO
JP2
JP3
JP4
JP7
75 V
—
–78 V
3xVNEG
–26 V
VNEG
2–3
2–3
1–2
2–3
90 V
–104 V
4xVNEG
—
–26 V
VNEG
1–2
—
—
2–3
N/A (external)
—
–52 V
2xVNEG
–26 V
VNEG
2–3
—
2–3
2–3
Rev. 0.2
2
AN74
2.4. Low Voltage VDD Supply
2.6. Initialization Steps
The low-voltage supply provides a switchable 3.3 V or
5 V output with a 1 A maximum load current. The
schematic for this power supply circuit is illustrated in
Figure 4 on page 5. The LT1375 IC integrated 1.5 A
bipolar switching transistor and current-sensing circuitry
eliminate external power transistors and sense resistors
and provide a high-efficiency VDD supply in a small
footprint. The switching frequency is internally fixed at
500 kHz and can be synchronized to higher frequencies
up to 1 MHz when a higher frequency signal (above
550 kHz) is provided on the SYNC pin. Table 3 provides
the jumper settings for selecting a 3.3 V or 5 V output as
well as for disconnecting the VDD supply altogether.
1. Configure all jumpers according to the application
requirements.
Table 3. VDD Supply Jumper Settings
Function
VDD output
enable
3.3 V/5 V
configuration
JP5
JP6
Comments
—
1–2
VDD connected
—
2–3
VDD disconnected
1–2
—
5 V selected
2–3
—
3.3 V selected
2.5. Frequency Synchronization
The LTC3704 is wired as a clock master device to
provide its switching frequency to the SYNC pin on the
LT1375 IC. To synchronize the frequency between the
two power circuits, R18 needs to be adjusted to set the
LTC3704 switching frequency at or above 550 kHz. The
LT1375 IC operates at its internal fixed 500 kHz and is
only synchronized with the LTC3704 frequency when it
senses the frequency on the SYNC pin going above
550 kHz. The SiLinkPS-EVB power circuits are
designed to operate safely with switching frequency on
the LTC3704 ranging from 200 kHz to 1 MHz.
2. (Optional) Plug in the input power source and
measure all outputs to verify correct settings.
3. Unplug input power source.
4. Assemble all ProSLIC daughter cards.
5. Plug in the input power source.
2.7. Cost-Optimized Design
The negative high-voltage circuit can be reduced for
cost optimization. The four equal VNEG outputs in
series arrangement provide some discrete voltage
adjustments to the outputs but require additional
rectifying diode circuits and increase cost. Figure 6 on
page 8 illustrates a lost-optimized design with two
negative outputs. The first secondary winding produces
a negative voltage according to the VNEG equation
described in the previous section to produce the VBLO
voltage. The other three secondary windings are
connected in series to produce a negative voltage with
an amplitude of 3 x VNEG. This output is connected in
series with the VBLO output to generate VBHI output
with a voltage level of 4 x VNEG.
The use of the simplified secondary rectifying circuit,
smaller transformer, and switching MOSFET lower the
component costs and also reduce the maximum output
power of the negative high-voltage circuit to 13 W.
Rev. 0.2
3
100pF
C20
R22
1.65k, 1%
R18
31.6k, 1%
3
1
J1
CONN HEADER 2x2/SM
R13
13k
C14
.001uF
CONN SOCKET 2x2/SM
JS2
R21
82k
C22
.001uF
4
2
3
1
4
2
3
1
3
1
2
4
2
4
1
3
1
3
Gate
IntVcc
Vin
Sense
IntVcc
R23
33.2k, 1%
Mode/Sync Gnd
Freq
NFB
Ith
Run
(Farside)
JP1
5
4
3
2
1
6
7
8
9
10
2
4
6
8
10
JS4
1
3
5
7
9
C23
.001uF
1
3
5
7
9
VBHI
VBLO
VDD
DC_Input_Diode
C21
4.7uF, 10V
IntVcc
CONN SOCKET 5x2
2
4
6
8
10
U2
LTC3704EMS
R17
4.7
C24
330uF 35V
DC_Input_Diode
D3
CMR3-02
Turn-on at 9.9V
Turn-off at 9.1V
R14
82k
DC_Input
R19
47
1
Gate
JS1
3
2
R20
.02, 1%
8
5
9
4
T1C
JS5
D12
B1100B
D11
B1100B
-52Vdc
D8
B1100B
-78Vdc
D5
B1100B
-104Vdc
CONN SOCKET 5x2
CONN SOCKET 5x2
10
3
C15
1uF, 25V
T1D
C11
1uF, 25V
T1E
C19
4.7uF, 50V
Q2
IRL540NS
7
C8
1uF, 25V
T1F
T1A
VP5
T1B
6
VBRNG
C17
10uF, 25V
-25Vdc
C12
10uF, 25V
C9
10uF, 25V
C5
10uF, 25V
R15
10k
R11
10k
R9
10k
R4
10k
9
7
5
3
1
JS3
10
8
6
4
2
10
8
6
4
2
CONN SOCKET 5x2
9
7
5
3
1
-52V
-78V
C13
1uF, 100V
C10
1uF, 100V
Post-regulator
Q1
VBLO
-25V
-50V
R6
10k
1
2
3
JP7
JP7
2-3
2-1
D10
47V
D9
47V
R8
4.7k
FZT953CT
Figure 3. High-Voltage Negative Battery Supply
C18
0.1uF
11
2
12
1
10
8
6
4
2
10
8
6
4
2
9
7
5
3
1
9
7
5
3
1
1
3
5
7
9
1
3
5
7
9
Rev. 0.2
2
4
6
8
10
4
2
4
6
8
10
R25
0
L2
10uH
R7
100k
-52V
-78V
VBLO
C25
4.7uF, 50V
C7
1uF, 100V
-96V
1
2
3
JP4
1
2
3
JP3
1
2
3
JP2
JP3
X
2-3
1-2
VBHI
VBRNG JP2
-96V
1-2
n/c
2-3
VBHI
-52V
-78V
-96V
VBRNG
JP4
2-3
1-2
1-2
AN74
Gate
DC_Input_Diode
C1
22uF, 6.3V
R26
10k
D2
1N4148
C3
1uF, 25V
C2
0.1uF
L1
15uH, 1.8A
R27
10k
Vc
FB
GND
SYNC
Rev. 0.2
8
7
6
5
Figure 4. Low-Voltage VDD Supply
R28
10k
LT1375CS8
BOOST
Vin
Vsw
SHDN
U1
C26
100pF
1
2
3
4
D1
B1100B
C4
4.7nF
R2
31.6k, 1%
R1
11.5k, 1%
1
2
3
JP6
VDD on
VDD off
VDD
1
2
3
JP5
5V
1-2
3.3V 2-3
R3
16.2k, 1%
VDD
5V or 3.3V
1A Max
AN74
5
Figure 5. PS Board Silkscreen
AN74
6
Rev. 0.2
AN74
3. Si Link PS–EVB Bill of Materials
Re fe re nce
C1
C2
C3,C8,C11,C15
C4
C5,C9,C12,C17
C7,C10,C13
C22,C14
C18
C16, C19
C20,C26
C21
C23
C24
D2
D3
D1,D5,D8,D11,D12
D9,D10
JP1
JP2,JP3,JP4,JP5,JP6,JP7
JS1,JS3,JS4,JS5
JS2
J1
L1
L2
Q1
Q2
R1
R2
R3
R4,R9,R11,R15,R26,R27,R28
R6
R7
R8
R13
R21,R14
R17
R18
R19
R20
R22
R23
R25
T1
U1
U2
De scription
22uF, 6.3V
0.1uF, 10V
1uF, 25V
4.7nF, 10V
10uF, 25V
1uF, 100V
.001uF, 25V
0.1uF, 35V
4.7uF, 50V
100pF, 25V
4.7uF, 10V
.001uF, 25V
330uF, 35V
1N4148
ES3A/B
B1100B
47V Zener
CONN HEADER 2x2/SM
HEADER 3X1
CONN SOCKET 5x2
CONN SOCKET 2x2/SM
CONN PW R 2-P
15uH, 1.8A
10uH
FZT953CT
IRL540NS
11.5k  , 1%
31.6k 
16.2k 
10k 
10k 
100k 
4.7k 
13k 
82k 
4.7 
120k 
47 
15m 
1.65k 
33.2k 
0
VP5
LT1375CS8
LTC3704EMS
Rev. 0.2
Pa rt Num be r
Ma nufa cture r
TMK432BJ106KM
Taiyo Yuden
18121C105KAT9A United Chemi-con
08055C102KAT
AVX
08053C104KAT
AVX
C5750X7R1H475K
TDK
08055A101KAT
AVX
LMK316BJ475
Taiyo Yuden
ES3A/B
B160B
Diodes, Inc.
Diodes, Inc.
Diodes, Inc.
TSM-102-02-T-DV
2303-6111TN
SSQ-1-05-24-F-D
SSM-102-L-DV-TR
ADC-002-1
UP1B-150
CTX32CT-100
FZT953CT
IRL540NS
Samtec
3M
Samtec
Samtec
Adam Tech
Coiltronics
Coiltronics
Zetex
Int. Rectifier
LRC1206-R015K
VPH5-0155
LT1375CS8
LTC3704CMS
IRC
Coiltronics
LTC
LTC
7
9
7
5
3
1
JS1
10
8
6
4
2
3
1
10
8
6
4
2
R22
1.87k, 1%
36k = 500kHz
20k = 1MHz
R18
36k
CONN SOCKET 5x2
9
7
5
3
1
R21
82k
C22
.01uF
680pF
C20
R13
16k
C14
.001uF
10~15Vdc
Input
3
1
D3
B340
5
4
3
2
1
Gate
IntVcc
Vin
Sense
IntVcc
6
7
8
9
10
JS3
C21
4.7uF, 10V
IntVcc
VBRNG
R17
4.7
C24
330uF 35V
CONN SOCKET 2x2
CONN SOCKET 5x2
JS2
R23
34.8k, 1%
Mode/Sync Gnd
Freq
NFB
Ith
Run
U2
LTC3704EMS
Turn-on at 9V
Turn-off at 8.2V
R14
82k
DC_Input
4
2
4
2
3
1
3
1
10
8
6
4
2
10
8
6
4
2
9
7
5
3
1
C18
0.1uF
1
6
2
8
3
Q2
Si4480DY
R20
7
1
3
5
7
9
10
3
9
4
8
5
7
6
1
3
5
7
9
C17
10uF, 25V
C5
2.2uF, 100V
2
4
6
8
10
2
4
6
8
10
JS4
In Proto:
R23 = 20.5k
R22 = 1.1k
C5 = 2 x 1uF / 100V in parallel
R4 = 3 x 10k in series
Q2 is upside-down
D12
B1100B
D4
ES1D
CONN SOCKET 5x2
C19
4.7uF, 50V
T1C
T1D
T1F
VP5
T1E
T1B
.015, 5%
VBHI
VBLO
DC_Input_Diode
VDD
4
5
11
2
12
1
T1: 10uH
T1A
R15
10k
R4
30k
JS5
C16
10uF, 25V
L2
10uH
L2 and C16 optional for lower output noise.
CONN SOCKET 5x2
-24Vdc
-96Vdc
Figure 6. Cost-Optimized Dual Output Battery Supply
9
7
5
3
1
1
3
5
7
9
1
3
5
7
9
Rev. 0.2
2
4
6
8
10
8
2
4
6
8
10
JP1
VBLO
VBHI
AN74
AN74
4. Cost-Optimized Dual Output Battery Supply Bill of Materials
Reference
C18
C5
C22, C14
C16*, C17
C19
C20
C21
C24
D3
D4
D12
L2*
Q2
R4
R13
R21, R14
R15
R17
R18
R20
R22
R23
T1
U2
Description
0.1 F, 25 V, X7R
2.2 F, 100 V, X7R
1 nF, 25 V, X7R
10 F, 25 V, X5R
4.7 F, 50 V, X7R
100 pF, 50 V, NP0
4.7 F, 10 V, X5R
330 F, 35 V
40 V, 3 A
200 V, 1 A
100 V, 1 A Shottky
10 H, 300 mA
80 V
30 k, 5%, 0.25 W
16 k, 5%, 0.1 W
82 k, 5%, 0.1 W
10 k, 5%, 0.1 W
4.7 , 5%, 0.1 W
36 k, 5%, 0.1 W
15 m, 5%, 0.25 W
1.87 k, 1%, 0.1 W
34.8 k, 1%, 0.1 W
10 H
Switching Regulator
Part Number
Manufacturer
08053C104KAT
AVX
C5750X7R2A225M TDK
TMK432BJ106KM
UMK325F475KH
08055A101KAT
LMK316BJ475
35CV330AX
B340
ES1D
B1100B
CTX32CT-470
Si4480DY
Taiyo Yuden
Taiyo Yuden
AVX
Taiyo Yuden
Sanyo
Diodes, Inc.
Diodes, Inc.
Diodes, Inc.
Coiltronics
Vishay
SP36-0100-10
LTC3704EMS
Transpower
LTC
Note: * Optional components used to reduce output noise if necessary.
Rev. 0.2
9
AN74
DOCUMENT CHANGE LIST
Revision 0.1 to Revision 0.2

New power supply schematics
Updated

10
Figures 3, 4, and 5.
Updated document to support two levels of VBATL
voltage.
Rev. 0.2
AN74
NOTES:
Rev. 0.2
11
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