Renesas RTKA211250DE0000BU User manual

Evaluation Board Manual
R16UZ0039EU0101 Rev.1.01 Page 1
Oct 7, 2022 © 2022 Renesas Electronics
The RTKA211250DE0000BU board evaluates the
RAA211250 (QFN version), a DC/DC synchronous
step-down regulator with programmable switching
frequency.
The RAA211250 supports a wide input voltage range
(from 4.5V to 30V) and adjustable output voltage. It
delivers up to continuous 3A output current with
premium load regulation and line regulation
performance.
Features
▪Simple and flexible design
▪4.5V to 30V VIN range
▪Convenient power conversion
Specifications
The following are the design specifications for the
RTKA211250DE0000BU:
▪Input voltage (VIN): 4.5V to 30V
▪Output voltage (VOUT): 3.3V
▪Maximum output current: 5A
Figure 1. Simplified Circuit
VIN
EN
BST
SW
FB
V
OUT
3.3V
V
IN
Up to 30V
PGND
R
IN1
R
IN2
C
IN
C
BOOT
L
R
FB1
R
FB2
RAA211250
C
OUT
3×47µF
EBIASFS
R
FS
VCCAGND
RTKA211250DE0000BU

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RTKA211250DE0000BU Evaluation Board Manual
Contents
1. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Operational Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Setup and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Board Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Schematic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Typical Performance Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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RTKA211250DE0000BU Evaluation Board Manual
1. Functional Description
The RAA211250 (QFN version) is an easy-to-use synchronous Buck switching regulator with integrated 70mΩ
(high-side) and mΩ(low-side) MOSFETs. The RTKA211250DE0000BU board demonstrates the operations of
RAA211250 (QFN version). The board allows you to evaluate the performance of the part with different application
circuits, and it also provides you a reference for board layout.
The manual includes a schematic (Figure 4), PCB layers (Figure 5 through Figure 8), performance data and
waveforms taken from the evaluation board (Figure 9 through Figure 16), and a full list of materials (Bill of
Materials).
1.1 Operational Characteristics
The board input voltage range is from 4.5V to 30V. The output voltage is set to 3.3V by default and can be
changed by R9and R10, as shown in Equation 1:
Renesas recommends using a 20kΩresistor for R10 and choose R9based on Equation 1.
1.2 Setup and Configuration
1. Populate a jumper on JP1(VIN shorted to EN).
2. Connect the power supply to the input terminals VIN(T1) and GND(T2). Connect the load to the output
terminals VOUT(T3) and GND(T4). Make sure the setup is correctly connected before applying any power or
load to the board.
3. Turn on the power supply and the part should start operating.
4. Verify that the output voltage is 3.3V and phase node waveforms can be monitored at J1.
(EQ. 1)
Figure 2. RTKA211250DE0000BU Board Setup
R9R10
Vout 0.8–
0.8
--------------------------
=
+
-LOAD
+
-
A

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RTKA211250DE0000BU Evaluation Board Manual
2. Board Design
2.1 Layout Guidelines
For detailed layout guidelines reference the Layout Guidelines section in the RAA211250 Datasheet.
Figure 3. RTKA211250DE0000BU Evaluation Board (Top)

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RTKA211250DE0000BU Evaluation Board Manual
2.2 Schematic Diagram
Figure 4. RTKA211250DE0000BU Schematic
TITLE: ENGINEER:
RELEASED BY:
DRAW N BY:
DATE: DATE:
ZHUANGYAO TANG ZHUANGYAO TANG
TP1
JP1
12
R2
DNP DNP
R1
C1
100UF
T2 T1
C2
4.7UF
TP3
4.7UF
C3
C4
0.1UF
TP4
C5
4.7UF
TP2
R3
0
FS
PG
AGND
VIN
FB
BST
SW
EBIAS
VCC
VIN VIN EN
PGND
U1
RAA211504GNP
R4
100K
R5
0
DNP
R6
C7
1UF
0.1UF
C6
R7
0
L1
3.3UH
12
J1
1 2
C8
47UF
47UF
C9
T4
47UF
C10
T3
12
J2
12
C11
TBD
R8
20
R10
20K
R9
62K
C12
TBD
R11
DNP
EN
EN
FB
FB
UNNAMED_1_CONN2_I41_IN1
UNNAMED_1_RAA211450_I49_4 UNNAMED_1_RAA211450_I49_5
UNNAMED_1_RAA211450_I49_8
UNNAMED_1_RAA211450_I49_9
UNNAMED_1_SMCAP_I23_A
UNNAMED_1_SMRES_I10_B
UNNAMED_1_SMRES_I24_B
VCC
VCC
VIN
VOUT
VOUT

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RTKA211250DE0000BU Evaluation Board Manual
2.3 Bill of Materials
Qty Ref Des Description Manufacturer Part Number
3C8, C9,
C10 CAP, SMD, 1210, 47µF, 10V, 10%, X7R, ROHS Murata GRM32ER71A476KE15L
1 C7 CAP, SMD, 0603, 1.0µF, 16V, 10%, X7R, ROHS TDK C1608X7R1C105K
1 C6 CAP, SMD, 0603, 0.1µF, 16V, 10%, X7R, ROHS Murata GCM188R71C104KA37D
1 C5 CAP, SMD, 0603, 4.7µF, 10V, 10%, X7S, ROHS Murata GRM188C71A475KE11D
1 C4 CAP, SMD, 0402, 0.1µF, 50V, 10%, X5R, ROHS TDK CGA2B3X5R1H104K050BB
2 C2, C3 CAP, SMD, 1206,10µF, 50V, 10%, X5R, ROHS TDK C3216X5R1H106K
1L1
COIL-PWR INDUCTOR, SMD, 6.6mmx6.4mm, 6.8µH, 20%,
6.5A, ROHS
Wurth
Electronics 74439344033
4T1, T2,
T3, T4
CONN-DBL TURRET, TH, 0.218x0.078 PCB MNT,
TIN/BRASS, ROHS Keystone 1502-1
2J1,J2
CONN-BRD-BRD, 1x2, TH, SOCKET, 1x64 STRIP, 2.54mm,
ST Mill-max 310-43-164-41-001000
1 TP3, TP4 CONN-MINI TEST PT, VERTICAL, BLK, ROHS Keystone 5001
1 TP1, TP2 CONN-MINI TEST POINT, VERTICAL, WHITE, ROHS Keystone 5002
1JP1
CONN-HEADER, 1x2, RETENTIVE, 2.54mm, 0.230x 0.120,
ROHS BERG/FCI 69190-202HLF
1 R10 RES, SMD, 0603, 20kΩ, 1/10W, 1%, ROHS Various Generic
1 R9 RES, SMD, 0603, 62kΩ, 1/10W, 1%, ROHS Panasonic ERJ-3EKF6202V
1 R8 RES, SMD, 0603, 20Ω, 1/10W, 1%, ROHS Panasonic ERJ-3EKF20R0V
3R3, R5,
R7 RES, SMD, 0603, 0Ω, 1/10W, ROHS Various Generic
1 R4 RES, SMD, 0603, 100kΩ, 1/10W, 1%, ROHS Various Generic
1 U1 IC-5A DC/DC Step-Down Regulator, 20P, QFN, ROHS Renesas RAA211250GNP#HA0
0 C1 CAP, SMD, 12x10, 47µF, 100V, 20%, ALUM.ELEC., ROHS Vishay MAL214699904E3
0
C11,
C12, R1,
R2, R6,
R11
DO NOT POPULATE N/A N/A

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RTKA211250DE0000BU Evaluation Board Manual
2.4 Board Layout
Figure 5. Top Layer
Figure 6. Second Layer

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RTKA211250DE0000BU Evaluation Board Manual
Figure 7. Third Layer
Figure 8. Bottom Layer

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RTKA211250DE0000BU Evaluation Board Manual
3. Typical Performance Graphs
VIN = 24V, VOUT = 3.3V, TA= +25°C, unless otherwise noted.
Figure 9. Efficiency vs Load Figure 10. Load Regulation
Figure 11. Output Ripple at No Load Figure 12. Output Ripple at Full Load
Figure 13. Enable On at Full Load with Internal SS Figure 14. Enable Off at Full Load with Internal SS
70
75
80
85
90
95
100
01234
5
Efficiency (%)
Output Current (A)
5Vin
12Vin
24Vin
3.283
3.284
3.285
3.286
3.287
3.288
01234
5
Output Voltage (V)
Output Current (A)
5Vin
12Vin
24Vin
40µs/Div
VOUT 20mV/Div
SW 5V/Div
2µs/Div
VOUT 20mV/Div
SW 5V/Div
VOUT 2V/Div
IL2A/Div
VPHASE 20V/Div
EN 5V/Div
PG 5V/Div
400µs/Div
VOUT 2V/Div
IL2A/Div
VPHASE 20V/Div
EN 5V/Div
PG 5V/Div
20µs/Div

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RTKA211250DE0000BU Evaluation Board Manual
4. Ordering Information
5. Revision History
Figure 15. Load Ramp from 50mA to 2.5A Figure 16. OCP by Short VOUT
Part Number Description
RTKA211250DE0000BU RAA211250 (QFN Version) Evaluation Board
Revision Date Description
1.01 Oct 7, 2022 Updated Figure 1.
1.00 May 9, 2022 Initial release
VIN = 24V, VOUT = 3.3V, TA= +25°C, unless otherwise noted. (Cont.)
VOUT 50mV/Div
IL1A/Div
SW 5V/Div
200µs/Div
Load 1A/Div
200µs/Div
VOUT 1V/Div
IL2A/Div
SW 20V/Div
VIN 1V/Div