MAXIM MAX8632EVKIT

19-3840; Rev 0; 10/05
MAX8632 Evaluation Kit
The MAX8632 evaluation kit (EV kit) is designed to evaluate the MAX8632 DDR power-supply solution for notebooks, desktops, and graphics cards. The EV kit board
produces VDDQ at the output of the synchronous PWM
buck, VTT at the output of the sourcing/sinking LDO linear
regulator, and VTTR at the output of the reference buffer.
The VDDQ output is preset to 1.8V and sources up to
10A. The VTT output is always VDDQ / 2 and can
source/sink up to 3A of peak current and 1.5A of continuous current. The VTTR output is also always VDDQ /2
and can source/sink up to 10mA.
The MAX8632 EV kit was conveniently designed with
jumpers to select the OVP/UVP, TON, SKIP, STBY, and
SHDN modes. The board’s default settings enable OVP
(overvoltage protection), 300kHz switching frequency,
low-noise PWM mode, VDDQ, VTT, and VTTR.
The VIN input accepts voltages from 7V to 20.5V and
VDD requires a 5V bias supply.
Features
♦ VDDQ Preset to 1.8V/10A
♦ VTT 0.9V Source/Sink 1.5A Continuous/3A Peak
♦ VTTR 0.9V Source/Sink 10mA
♦ VIN Range: 7V to 20.5V
♦ Optimized Switching Frequency: 300kHz
♦ Overvoltage/Undervoltage Protection
♦ Independent Shutdown and Standby Controls
♦ Power OK
Ordering Information
PART
TEMP RANGE
IC PACKAGE
MAX8632EVKIT
0°C to +70°C
28 Thin QFN 5mm x 5mm
Component List
DESIGNATION QTY
C1
C2, C4A,
C4B
C3, C6
C5
C7, C10
C8A, C8B, C8C
DESCRIPTION
1
0.1µF ±10%, 16V X7R (0603) ceramic
capacitor
Taiyo Yuden EMK107BJ104MA
3
10µF ±10%, 6.3V X5R (0805) ceramic
capacitors
Kemet C0805C106K9PAC
Taiyo Yuden JMK212BJ106MG
2
1µF ±10%, 10V X5R (0603) ceramic
capacitors
TDK C1608X5R1A105K
1
4.7µF ±20%, 6.3V (0805) X5R ceramic
capacitor
TDK C2012X5R0J475M
2
0.22µF ±20%, 16V X7R (0603)
ceramic capacitors
TDK C1608X7R1C224M
3
10µF ±20%, 25V X5R (1210) ceramic
capacitors
Taiyo Yuden TMK325BJ106MM
TDK C3225X5R1E106M
DESIGNATION QTY
DESCRIPTION
C9
1
4700pF ±10%, 50V X7R (0603)
ceramic capacitor
Kemet C0603C472K5RAC or
equivalent
C11, C12
2
150µF, 4V, 18mΩ POS capacitors
Sanyo 4TPE150MI
D1
1
Schottky diode, 30V, 100mA (SOD-323)
Central CMDSH-3
JU1–JU4, JU6
5
3-pin headers, 0.1in center
36-pin header, 0.1in center
Sullins PTC36SAAN or equivalent
Digi-key S1012-36-ND
L1
1
1.4µH, 15.5A, 2.8mΩ power inductor
Sumida CEP125-1R4MC-U
Q1
1
30V, 12mΩ (SO-8) n-channel MOSFET
International Rectifier IRF7821
Q2
1
30V, 4mΩ (SO-8) n-channel MOSFET
International Rectifier IRF7832
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
Evaluates: MAX8632
General Description
Evaluates: MAX8632
MAX8632 Evaluation Kit
Component List (continued)
DESIGNATION QTY
DESCRIPTION
R1
1
10Ω ±5% (0603) resistor
R2, R3, R4
3
100kΩ ±5% (0603) resistors
R5
1
36.5kΩ ±1% (0603) resistor
R13
1
20Ω ±5% (0603) resistor
R18
1
0Ω ±5% (0603) resistor
U1
1
Integrated DDR power supply
(28-pin, 5mm x 5mm, Thin QFN)
MAX8632ETI+
—
5
Shunts
Sullins STC02SYAN
Digi-key S9000-ND or equivalent
Component Suppliers
SUPPLIER
PHONE
631-435-1110 www.centralsemi.com
International
Rectifier
310-322-3331 www.irf.com
Kemet
864-963-6300 www.kemet.com
Sanyo USA
619-661-6835 www.sanyo.com
Sumida
Taiyo Yuden
7) Connect the 12VDC power supply across the VIN
pad and the corresponding GND pad.
8) Turn on both of the power supplies.
9) Set JU4 (1-2). This turns VDDQ on.
10)Using one of the DVMs, verify that the VDDQ voltage
between the VDDQ and PGND pads is 1.8V (±2%).
11)Using the other DVM, verify that the VTT voltage
between the VTT and PGND pads is 0.9V (±2%).
Detailed Description
Jumper Selection
Table 1. Overvoltage/Undervoltage
Control Input (OVP/UVP)
JUMPER
SHUNT
POSITION
847-545-6700 www.sumida.com
JU2
1-2
Disable OVP and UVP.
800-348-2496 www.t-yuden.com
JU2
1-3
Enable UVP. Disable OVP.
847-803-6100 www.component.tdk.com
JU2
1-4*
Enable OVP and UVP.
JU2
Open
Note: Indicate that you are using the MAX8632 when contacting these component suppliers.
Recommended Equipment
• 5VDC power supply (500mA rated)
• 7VDC to 20.5VDC power supply (5A rated)
• Two digital voltmeters (DVM)
Quick Start
The MAX8632 EV kit is fully assembled and tested. Follow
these steps to verify board operation. Do not turn on the
power supplies until all connections are completed.
1) Ensure a shunt is placed across pins 1-4 of jumper
JU2 to enable OVP and UVP.
2) Ensure jumper JU1 is open to set the switching frequency to approximately 300kHz.
2
6) Connect the 5VDC power supply across the VDD
pad and the GND pad nearest VIN.
WEBSITE
Central
Semiconductor
TDK
3) Ensure a shunt is placed across pins 1-2 of jumper
JU3 to enable low-noise PWM mode.
4) Ensure a shunt is placed across pins 2-3 of jumper
JU4 to disable the VDDQ buck output.
5) Ensure a shunt is placed across pins 2-3 of jumper
JU6 to set the board in normal operation mode.
DESCRIPTION
Enable OVP. Disable UVP.
*Default position.
Note: Refer to the MAX8632 data sheet for additional information on OVP/UVP.
Setting the Buck Regulator Output
Voltage (VDDQ)
The output voltage of the buck regulator is preset to
1.8V on the MAX8632 EV kit for DDR memory applications. To pin-strap the output voltage to 2.5V, follow the
steps below:
1) Remove R18.
2) Solder the 0Ω resistor from step 1 in the R9 location.
Refer to the MAX8632 data sheet to change the external
components for optimum performance.
_______________________________________________________________________________________
MAX8632 Evaluation Kit
Table 4. Shutdown Control Input (SHDN)
JUMPER
SHUNT
POSITION
DESCRIPTION
JUMPER
SHUNT
POSITION
DESCRIPTION
JU1
1-2
600kHz switching frequency
JU4
1-2
The VDDQ buck output is enabled.
JU1
1-3
450kHz switching frequency
JU1
1-4
200kHz switching frequency
JU4
2-3*
The VDDQ buck output is shut
down.
JU1
Open*
300kHz switching frequency
*Default position.
Note: Refer to the MAX8632 data sheet for additional information on TON.
Table 3. Pulse-Skipping Control Input
(SKIP)
JUMPER
SHUNT
POSITION
JU3
1-2*
Low-noise PWM mode.
JU3
2-3
Pulse-skipping mode.
DESCRIPTION
*Default position.
Note: Refer to the MAX8632 data sheet for additional information on SKIP.
*Default position.
Note: Refer to the MAX8632 data sheet for additional information on SHDN.
Table 5. Standby Control Input (STBY)
JUMPER
SHUNT
POSITION
JU6
2-3
The VTT output is shut down.
JU6
1-2*
Normal operation.
DESCRIPTION
*Default position.
Note: Refer to the MAX8632 data sheet for additional information on STBY.
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Evaluates: MAX8632
Table 2. On-Time Selection Input (TON)
4
VDD
POK2
POK1
GND
VTTR
0.9V AT 10mA
GND
VTT
0.9V AT 3A
R6
OPEN
R7
OPEN
J15
J3
J14
J2
J13
J1
C14
OPEN
REF
3
VDD
REF
R5
36.5kΩ
C10
0.22µF
2
VDD
C4A
10µF
C9
4700pF
R4
100kΩ
2
JU2 4
1
3
REF
R3
100kΩ
4
1 JU1
VDD
R16
OPEN
R2
100kΩ
C6
1µF
C4B
10µF
R17
SHORT
C16
OPEN
9
8
4
REFIN
VTTI
SS
ILIM
R14
SHORT
Figure 1. MAX8632 EV Kit Schematic
_______________________________________________________________________________________
TAB
29
TPO
28
SKIP
25
C1
0.1µF
R19
OPEN
MAX8632
U1
14
13
OVP/UVP
TON
POK2
POK1
GND
VTTR
PGND2
VTT
VTTS
3 REF
2
1
6
5
24
10
11
12
C2
10µF
VTTI
JP1
VIN
2
VDD
OUT
FB
STBY
SHDN
PGND1
DL
LX
DH
BST
VDD
16
15
7
27
23
21
19
18
20
22
26
17
3
3
1
2
JU4
VDD
R11
SHORT
R10
SHORT
JU3
1
VDD
AVDD
R13
20Ω
R9
OPEN
R8
OPEN
3 JU6
1
2
R18
0Ω
Q2
IRF7832
VDD
Q1
J5
J7
C7 IRF7821
0.22µF
D1
CMDSH-3
R1
10Ω
C3
1µF
VDD
STBY
SHDN
C15
OPEN
R12
OPEN
C8A–C8C
3 x 10µF
25V L1
1.4µH
VDD
C5
4.7µF
C11
150µF
4V
J12
J10
J11
C12
150µF
4V
VDD
4.5V TO 5.5V
PGND
VIN
7V TO 20.5V
C13
OPEN
J8
J9
PGND
VDDQ
1.8V AT 10A
Evaluates: MAX8632
MAX8632 Evaluation Kit
MAX8632 Evaluation KitMAX8632 Evaluation Kit
Evaluates: MAX8632
Figure 2. MAX8632 EV Kit Component Placement Guide—Component Side
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5
Evaluates: MAX8632
MAX8632 Evaluation Kit
Figure 3. MAX8632 EV Kit PC Board Layout—Component Side
6
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MAX8632 Evaluation Kit
Evaluates: MAX8632
Figure 4. MAX8632 EV Kit PC Board Layout—Inner Layer 2
_______________________________________________________________________________________
7
Evaluates: MAX8632
MAX8632 Evaluation Kit
Figure 5. MAX8632 EV Kit PC Board Layout—Inner Layer 3
8
_______________________________________________________________________________________
MAX8632 Evaluation KitMAX8632 Evaluation Kit
Evaluates: MAX8632
Figure 6. MAX8632 EV Kit PC Board Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 9
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.