CS51221: High Power Boost (Thermal Printer)

Design Note – DN06055/D
Power Supply PSU
Device
CS51221
Application
Input
Voltage
Output
Voltage
Output
Current
Topology
Cash Drawer
12 V
24V
4A
Boost
Table 1: CS51221 Cash Drawer Power Supply
Characteristic
Output Voltage
Output Current
Oscillator Frequency
Output Voltage Ripple
Min
23.56
.5
Max
26.04
20
140
100
Load Regulation
Iout = (0.1-8.3A) Vin= 12V
Size
Typ
24.72
150
300
-1.33
Length
80
Width Height
59
31
Unit
V
A
kHz
mVpkpk
mV/A
mm
Figure 1: Demonstration Board Picture
Circuit Description
The design must minimize the use of through hole components, designed as small as possible on a 4 layer PCB,
and only populated on one side. The power supply is required to maintain an 24.7V output while with an input
of 12V.
Rev 2 - December, 2008
Table 2: CS51221 Cash Drawer Power Supply Compliance Matrix
Item
1
2
3
4
5
6
7
8
9
Description
Minimum
Maximum
23.56 V
26.04 V
24.72 V
PASS
21.08 V
26.04 V
24.72 V
PASS
100 mV
50 mV
PASS
300 mV
26.04 V
149 mV
MIN = 24.24 V
MAX = 24.95 V
PASS
Tolerance Line and Load
Regulation (USB)
Tolerance Line and Load
Regulation (Cash Drawer
Interface)
Ripple Voltage Nominal
Current (peak to peak)
Noise, HF ripple (peak to
peak)
Transient Response
1.5A to 4.5A
(10 A/us slew rate)
Transient Response
1.5A to 7A
(10 A/us slew rate)
Transient Response
0A to 20A
(10 A/us slew rate)
Transient Response
2A to 16A
(.014 A/us slew rate)
Transient Response
0A to 16A
(.014 A/us slew rate)
22.8 V
22.8 V
19.84 V
22.32 V
22.32 V
26.04 V
26.04 V
26.04 V
26.04 V
The design has the following features:
• Adjustable cycle by cycle current limiting
• Over voltage Shutoff
• Under voltage shutoff
• Can be synchronized to a higher frequency
• Programmable soft start
• Voltage feed forward
Rev 2 - December, 2008
Measured
Pass/
Fail
PASS
MIN = 24.24 V
MAX = 24.85 V
PASS
MIN = 21.23 V
MAX = 25.65 V
PASS
MIN = 23.97 V
MAX = 25.21 V
PASS
MIN = 23.8 V
MAX = 24.95 V
PASS
Performance Information
The following figures show typical performance of the evaluation board.
Dell CS51221 Efficiency 12V to 24V
100
Efficiency (%)
95
90
85
80
75
70
65
60
0
1
2
3
4
5
6
Output Current (A)
Figure 2: CS51221 Efficiency at 12V with a 24.7V Output Voltage
Output Voltage (V)
Dell CS51221 Load Regulation
24.725
24.724
24.723
24.722
24.721
24.72
24.719
24.718
24.717
24.716
24.715
0
1
2
3
4
Output Current (A)
Figure 3: CS51221 Load Regulation
Rev 2 - December, 2008
5
6
Schematic
Figure 4: CS51221 Schematic
Rev 2 - December, 2008
Figure 5: CS51221 Top Layout
Rev 2 - December, 2008
Figure 6: CS51221 Top Inner Layout
Rev 2 - December, 2008
Figure 7: CS51221 Bottom Inner Layout
Rev 2 - December, 2008
Figure 8: CS51221 Bottom Inner Layout
Rev 2 - December, 2008
Table 3: CS51221 BOM
Designator
Quantity
Description
Value
Tolerance
Footprint
Manufacturer
Manufacturer Part Number
C5
1
Ceramic Chip Capacitor 10V
330n
±20%
805
AVX Corporation
0805ZC334JAT2A
C8
1
Ceramic Chip Capacitor 25V
0.1uF
±20%
603
AVX Corporation
06033C104MAT2A
C2
1
Ceramic Chip Capacitor 25V
0.1uF
±20%
603
AVX Corporation
06033C104MAT2A
C12
1
Ceramic Chip Capacitor 10V
1.5nF
±10%
603
AVX Corporation
0603YC152KAT2A
C6
1
Ceramic Chip Capacitor 10V
1nF
±10%
603
AVX Corporation
0603ZC102KA72A
C4
1
Ceramic Chip Capacitor 6.3V
1uF
±10%
603
AVX Corporation
06036D105KAT2A
C20
1
Ceramic Chip Capacitor 25V
1uF
±20%
603
AVX Corporation
06033D105MAT2A
C10
1
Ceramic Chip Capacitor 50V
2.2nF
±5%
603
AVX Corporation
06035C222JAT2A
C11
1
Ceramic Chip Capacitor 16V
82nF
±10%
603
AVX Corporation
0603YC823KAT2A
C24
1
Ceramic Chip Capacitor 6.3V
1.2n
±5%
805
AVX Corporation
08056A122JAT2A
C16
1
Ceramic Chip Capacitor 100V
1.2nF
±10%
1206
AVX Corporation
12061A122KAT2A
12061C102KAT2A
C3
1
Ceramic Chip Capacitor 100V
1nF
±10%
1206
AVX Corporation
C21 C23
2
Ceramic Chip Capacitor 50V
1uF
±10%
1206
AVX Corporation
12065C105KAT2A
C1
1
Ceramic Chip Capacitor 50V
4.7uF
±20%
1812
TDK Corporation
C4532X7R1H475M
U1
C7 C9 C13-15
C17-19
1
Mode PWM Controller
3V Ref
NA
SOIC 16
ON Semiconductor
CS51221EDR16G
8
Electrolytic Capacitor
680uF
±20%
12.5X25
United Chemicon
EKZE500ELL681MK30S
D1
1
Schottky Power Rectifier
40A 100V
NA
D2PAK 3 LEAD
ON Semiconductor
MBRB41H100CTT4G
Q5
1
NPN Transistor
40V 200mA
NA
SOT-23
ON Semiconductor
MMBT3904TT1G
Z1
1
Zener Diode
14V
±5%
SOD-123
ON Semiconductor
MMSZ5244BT1G
U2-3
2
N MOSFET 8.1mOhm
60V 50A
NA
DPAK
Infineon
IPB081N06L3G
R5
1
SMT Resistor
49.9k
±1.0%
1206
Vishay
CRCW120649K9FKEA
R14
1
SMD Resistor
1.02k
±1.0%
603
Vishay / Dale
CRCW06031K02FKEA
CRCW06031K58FKEA
R3
1
SMD Resistor
1.58k
±1.0%
603
Vishay / Dale
R20
1
SMD Resistor
1k
±5.0%
603
Vishay / Dale
CRCW06031K00JNEA
R9
1
SMD Resistor
20R0
±1.0%
603
Vishay / Dale
CRCW060320R0FKEA
R21
1
SMD Resistor
27.4k
±1.0%
603
Vishay / Dale
CRCW060327K4FKEA
R2
1
SMD Resistor
3.09k
±1.0%
603
Vishay / Dale
CRCW06033K09FKEA
R7
1
SMD Resistor
40.2k
±1.0%
603
Vishay / Dale
CRCW060340K2FKEA
R23
1
SMD Resistor
41.2k
±1.0%
603
Vishay / Dale
CRCW060341K2FKEA
R13
1
SMD Resistor
49.9k
±1.0%
603
Vishay / Dale
CRCW060349K9FKEA
R1
1
SMD Resistor
57.6k
±1.0%
603
Vishay / Dale
CRCW060357K6FKEA
Rev 2 - December, 2008
Designator
Quantity
Description
Value
Tolerance
Footprint
Manufacturer
Manufacturer Part Number
R26
1
SMD Resistor
6.04k
±1.0%
603
Vishay / Dale
CRCW06036K04FKEA
R25
1
SMD Resistor
8.2k
±1.0%
603
Vishay / Dale
CRCW06038K20FKEA
R8 R12
2
SMD Resistor
0R0
±5.0%
1206
Vishay / Dale
CRCW12060000Z0EA
R11 R15
2
SMD Resistor
10R0
±5.0%
1206
Vishay / Dale
CRCW120610R0FKEA
R10
1
SMD Resistor
4.99k
±1.0%
1206
Vishay / Dale
CRCW12064K99FKEA
R6
1
SMD Resistor
8.06K
±1.0%
1206
Vishay / Dale
CRCW12068K06FKEA
R4
1
SMD Resistor
5mOhm
±1.0%
4527
Vishay / Dale
WSR55L00F
L2
1
SMT Inductor 0.17 mOhm
.1 uH
±10%
7.5mmX7.6mm
Coilcraft
SLC7649S-101KL
L1
1
SMT Inductor 1.8 mOhm
10 uH
±10%
27.94mmX27.9mm
Coilcraft
SER2918H-103
Rev 2 - December, 2008
Figure 9: Vin = 12V Vout =24V Iout = 4A 149 mVpp High Frequency 50mV Fundamental
Rev 2 - December, 2008
Figure 10: Transient Response 1.5A to 4.5A with a Slew Rate of 10A/us for a Duration of 300ms and a Period of 1800ms
Rev 2 - December, 2008
Figure 11: Transient Response 1.5A to 7A with a Slew Rate of 10A/us for a Duration of 210ms and a Period of 1050ms
Rev 2 - December, 2008
Figure 12: Transient Response 0A to 20A with a Slew Rate of 10A/us for a Duration of 2ms and a Period of 10ms
Rev 2 - December, 2008
Figure 13: Transient Response 2A to 16A with a Slew Rate of 0.014A/us and a Period of 2ms
Rev 2 - December, 2008
Figure 14: Transient Response 0A to 16A with a Slew Rate of 0.014A/us and a Period of 3.4 ms
Rev 2 - December, 2008
Figure 15: 12V Frequency Response 1.3 kHz at 51 Degrees of Phase Margin 4A Load
Rev 2 - December, 2008
Figure 16: Thermal Image of PCB at 12V with a 4A Load and 25C Ambient
Rev 2 - December, 2008
1
© 2009 ON Semiconductor.
Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor does ON Semiconductor convey any license
to its or any third party’s intellectual property rights. This document is provided only to assist customers in evaluation of the referenced circuit implementation and the
recipient assumes all liability and risk associated with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of
its products at any time, without notice.
Design note created by Tim Kaske and Bryan McCoy, e-mail: [email protected] ; [email protected]
Rev 2 - December, 2008
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