19-3299; Rev 0; 5/04
MAX1549 Evaluation Kit
General Description
The MAX1549 evaluation kit (EV kit) demonstrates the MAX1549’s standard application circuit. This DC-DC converter steps down high-voltage batteries and/or AC adapters, generating precision low-voltage chipset and RAM power supplies for notebook computers. The MAX1549 EV kit provides a dynamically adjustable 0.7V to 1.5V output voltage range (OUT1), and a fixed 2.5V output voltage (OUT2) from a 5V to 20V battery input range. It delivers up to a 6A output current for OUT1, and up to a 4A output current for OUT2, with greater than 90% efficiency. The EV kit operates at 300kHz switching frequency and has superior line- and load-transient response. This EV kit is a fully assembled and tested circuit board. It is capable of evaluating other dynamically adjustable output voltages in the 0.5V to 2.0V range by changing R10–R14. Other fixed output voltages in the 0.5V to 2.7V range can be evaluated by changing R20 and R21. ♦ 5V to 20V Input Voltage Range ♦ Four Digitally Selectable Operating Voltages (OUT1) ♦ Dynamically Selectable Output Voltages 0.7V/1.0V/1.3V/1.5V (OUT1, Adjustable from 0.5V to 2.0V) ♦ Fixed 2.5V Output Voltage (OUT2, Adjustable from 0.5V to 2.7V) ♦ 6A Output Current (OUT1) ♦ 4A Output Current (OUT2) ♦ 300kHz Switching Frequency ♦ Independent Power-Good Outputs ♦ Low-Profile Components ♦ Fully Assembled and Tested
Features
Evaluates: MAX1549
Ordering Information
PART MAX1549EVKIT TEMP RANGE 0 C to +70 C
o o
IC PACKAGE 40 Thin QFN (6mm x 6mm)
Component List
DESIGNATION C1, C19 C2 QTY 0 1 DESCRIPTION Not installed (E-case) 470µF, 2.5V, 6mΩ low-ESR polymer capacitor (E-case) Sanyo 2R5TPD470M6 220µF, 4V, 15mΩ low-ESR capacitor (D-case) Sanyo 4TPE220MF 10µF ±20%, 25V X5R ceramic capacitors (1812) Taiyo Yuden TMK432BJ106KM or TDK C4532X5R1E106M Not installed (1812) 0.1µF ±10%, 50V X7R ceramic capacitors (0603) Murata GRM188R71H104K or equivalent Not installed (0603) C12 1 DESIGNATION QTY DESCRIPTION 2.2µF, 10V X5R ceramic capacitor (0612) TDK C1632X5R1A225KTB09N 470pF ±10%, 50V X7R ceramic capacitors (0603) Murata GRM188R71H471K or equivalent 0.22µF, 16V X5R ceramic capacitor (0805) Taiyo Yuden EMK212BJ224KG 1µF ±20%, 10V X5R ceramic capacitor (0805) Taiyo Yuden LMK212BJ105KG or TDK C2012X7R1C105MKT 100pF ±5%, 50V C0G ceramic capacitors (0603) Murata GRM1885C1H101J or equivalent
C13, C16
2
C3
1
C14
1
C4, C5
2
C6, C7
0
C15
1
C8, C9
2
C17, C18
2
C10, C11, C20–C26
0
________________________________________________________________ Maxim Integrated Products
1
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.
MAX1549 Evaluation Kit Evaluates: MAX1549
Component List (continued)
DESIGNATION QTY DESCRIPTION 10µF ±20%, 6.3V X5R ceramic capacitors (0805) TDK C2012X5R0J106M or Taiyo Yuden AMK212BJ106MG 1A, 30V Schottky diodes Nihon EP10QY03 or Toshiba CRS02 100mA, 30V dual Schottky diode (SOT23) Central Semiconductor CMPSH-3A 3-pin headers Not installed, 4-pin header 2-pin headers Shunts 1.5µH, 7A power inductor Sumida CDRH105R-1R5 4.7µH, 5.7A power inductor Sumida CDRH124-4R7 N-channel MOSFETs (8-pin SO) Fairchild FDS6612A N-channel MOSFETs (8-pin SO) Fairchild FDS6670A DESIGNATION R1 QTY 1 DESCRIPTION 0.012Ω ±1%, 0.5W resistor (2010) IRC LR2010-01-R012-F or Dale WSL-2010-R012F 0.015Ω ±1%, 0.5W resistor (2010) IRC LR2010-01-R015-F or Dale WSL-2010-R015F Not installed (short PC trace) (0603) 100kΩ ±5% resistors (0603) 10Ω ±5% resistor (0805) 100kΩ ±1% resistors (0603) 301kΩ ±1% resistor (0603) 487kΩ ±1% resistor (0603) 150kΩ ±1% resistor (0603) 66.5kΩ ±1% resistor (0603) Not installed (0603) 0Ω ±1% resistor (0603) MAX1549ETL (40-pin thin QFN 6mm x 6mm) Rubber bumpers MAX1549 PC board
C27, C28
2
R2
1
D1, D2
2
R3–R6, R22, R23 R7, R8, R27, R28 R9 R10, R15–R18 R11 R12 R13 R14
0 4 1 5 1 1 1 1 0 1 1 4 1
D3 JU1, JU2, JU6 JU3 JU4, JU5 JU1 (1,2) JU2 (1,2) JU6 (1,2) L1 L2 N1, N3 N2, N4
1 3 0 2 4 1 1 2 2
R19, R20, R24, R25, R26, R29, R32 R21 U1 None None
Component Suppliers
SUPPLIER Central Semiconductor Dale-Vishay Fairchild IRC Murata Nihon Sanyo Sumida Taiyo Yuden TDK PHONE 516-435-1110 402-564-3131 408-721-2181 361-992-7900 770-436-1300 847-843-7500 619-661-6835 708-956-0666 800-348-2496 847-390-4373 FAX 516-435-1824 402-563-6296 408-721-1635 361-992-3377 770-436-3636 847-843-2798 619-661-1055 708-956-0702 847-925-0899 847-390-4428 WEBSITE www.centralsemi.com www.vishay.com www.fairchildsemi.com www.irctt.com www.murata.com www.niec.co.jp www.sanyovideo.com www.sumida.com www.t-yuden.com www.component.tdk.com
Note: Indicate that you are using the MAX1549 when contacting these component suppliers.
Quick Start
Equipment Needed
• 5V to 20V power supply, battery, or notebook AC adapter
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• DC bias power supply, 5V at 100mA • Dummy loads capable of sinking 6A • Digital multimeters (DMMs) • 100MHz dual-trace oscilloscope
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MAX1549 Evaluation Kit
Procedure
1) Ensure that the circuit is connected correctly to the supplies and dummy loads prior to applying any power. 2) Verify that the shunts are installed across pins 1 and 2 of jumper JU1 (ON1 high), pins 1 and 2 of jumper JU2 (ON2 high), and pins 1 and 2 of JU6 (SKIP high, forced PWM). 3) Turn on battery power prior to +5V bias power; otherwise, the output UVLO timer times out and the FAULT latch is set, disabling the regulator outputs until +5V power is cycled or ON1/ON2 is toggled. 4) Verify that the output voltages are V OUT1 = 1.5V, VOUT2 = 2.5V.
Evaluates: MAX1549
Table 3. Jumpers JU3 Functions (Switching-Frequency Selection)
JU3 1 and 2 1 and 3 1 and 4 Not Installed (Default) TON PIN Connected to VCC Connected to REF Connected to GND Floating FREQUENCY (kHz) 400 200 100 300 (As Shipped)
Detailed Description
Jumper Settings
Note: Do not change the operating frequency without first recalculating component values. The frequency has a significant effect on preferred inductor value, peak current-limit level, MOSFET heating, PFM/PWM switchover point, output noise, efficiency, and other critical parameters.
Table 1. Jumper JU1 Functions (Output Voltage OUT1 Control)
JU1 1 and 2 (Default) 2 and 3 Not Installed ON1 PIN OUT1 OUT1 enabled, VOUT1 = 1.5V. OUT1 depends on gate inputs G0 and G1. See Table 4. OUT1 shutdown mode OUT1 operation depends on the external ON1 signal levels.
Table 4. Jumpers JU4 and JU5 Functions (Gate Inputs G0 and G1)
JU4 Not Installed G0 = GND Installed G0 = VCC Not Installed G0 = GND Installed G0 = VCC JU5 Not Installed G1 = GND Not Installed G1 = GND Installed G1 = VCC Installed G1 = VCC OUT1 1.50V (Default) 1.30V 1.00V 0.70V
Connected to VCC.
Connected to GND. ON1 must be driven by an external signal connected to ON1 pad.
Table 2. Jumper JU2 Functions (Output Voltage OUT2 Control)
JU2 1 and 2 (Default) 2 and 3 Not Installed ON2 PIN Connected to VCC. Connected to GND. ON2 must be driven by an external signal connected to ON2 pad. OUT2 OUT2 enabled, VOUT2 = 2.5V OUT2 shutdown mode OUT2 operation depends on the external ON2 signal levels.
Table 5. Jumper JU6 Functions (Low-Noise Mode)
JU6 1 and 2 (Default) 2 and 3 SKIP PIN OPERATIONAL MODE Low-noise mode, OUT1 and OUT2 are in forced PWM mode. OUT1 and OUT2 are in pulse-skipping mode.
Connected to VCC.
Connected to GND.
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MAX1549 Evaluation Kit Evaluates: MAX1549
Evaluating Other Dynamic Output Voltages (OUT1)
The EV kit output is preset to 0.7V/1.0V/1.3V/1.5V (OUT1). G0 (JU4) and G1 (JU5) gate inputs select the OUT1 voltage (see Table 4). However, OUT1 can also be adjusted between 0.5V and 2.0V by selecting R10– R14 values. Refer to the MAX1549 data sheet Output Voltage section for more information. nected to VCC (R20 = open, R21 = open, R19 = 0). OUT2 can also be adjusted from 0.5V to 2.7V by using a resistive voltage-divider formed by R20 and R21 (R19 = open). The MAX1549 regulates FB2 to a fixed reference voltage (0.5V). The adjusted output voltage is: VOUT2 = VFB2(1 + R20 / R21) where VFB2 = 0.5V A 330pF to 1000pF feed-forward bypass capacitor (C26) reduces duty-cycle jitter and feedback noise. Refer to the MAX1549 data sheet for selection of output-capacitor and inductor values for different output voltages.
Evaluating Other Fixed Output Voltages (OUT2)
The MAX1549 provides a fixed 2.5V output (OUT2) when FB2 is connected to GND (R20 = open, R21 = 0, R19 = open) or a fixed 1.8V output when FB2 is con-
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MAX1549 Evaluation Kit Evaluates: MAX1549
VCC R14 66.5kΩ 1% R13 150kΩ 1% R12 487kΩ 1%
VOUT1 37 OD1 OUT1 PGOOD1 38 OD2 CSL1 34 33 35
R7 100kΩ PGOOD1 C22 OPEN R6 SHORT (PC TRACE)
VREF
R10 100kΩ 1% C13 470pF R11 301kΩ 1% VCC R9 10Ω
39 40
OD3 REFIN
CSH1
36 R22 SHORT (PC TRACE) C9 0.1µF C23 OPEN BST1 N1 4
R5 C10 SHORT OPEN (PC TRACE)
VDD
C14 0.22µF
VREF
1 GND 2 N.C. 3 REF
VIN 5 6
BST1
29
VIN 20V MAX C6 OPEN
8 7
4 C15 1µF R15 VREF 100kΩ 1% R16 100kΩ 1% C17 100pF C16 470pF
DH1 VCC CC1 N.C. LX1 U1
32 31 30
C4 10µF 25V
GND L1 1.5µH R1 0.012Ω 1% C20 OPEN C1 OPEN VOUT1 VOUT1 0.7V TO 1.5V AT 6A C28 10µF 6.3V
1 5 6 N2
3 2 8 D1
5
7
R29 OPEN
6
MAX1549 ILIM1
DL1
27 VCC JU6 1 2 VCC 25 26 23 22 20 19 21 C12 2.2µF 3 VBIAS +5V
4 3 1 SKIP 2
C2 470µF 2.5V
GND
R17 VREF 100kΩ 1%
SKIP 7 C18 100pF ILIM2 N.C. VDD VCC G0 JU4 8 VCC R27 100kΩ JU5 VCC G1 9 R28 100kΩ G1 DL2 G0 PGND BST2 N.C. DH2 LX2
28
VDD
R18 100kΩ 1%
D3
3
1 R23 SHORT (PC TRACE) C8 0.1µF
R 2 5 6 4 1 5 6
L
BST1 8 7 N3 3 2 7 8 D2
VIN C21 OPEN R2 0.015Ω 1% C3 220µF 4V VOUT2 VOUT2 C19 OPEN C27 10µF 6.3V
C5 10µF 25V
C7 OPEN
R32 OPEN L2 4.7µH
24
4 1
N4 3 2 R4 SHORT (PC TRACE)
VREF
R25 R24 OPEN OPEN R26 OPEN VREF
10
FBLANK
CSH2
14
C25 OPEN C11 OPEN VCC C24 OPEN R8 100kΩ
VCC 400kHz OPEN 300kΩ 11 VCC 4
CSL2
15
R3 SHORT (PC TRACE)
JU3 2 200kHz 3 1
VCC
FSEL 18 16
100kHz ON1 VCC JU2 ON2 1 2 3
PG00D2
JU1
1 2 12 3
PG00D2 ON1 FB2
R19 OPEN
VOUT2 R20 OPEN C26 OPEN
VOUT2 17 R21 0Ω
OUT2 13 ON2
Figure 1. MAX1549 EV Kit Schematic _______________________________________________________________________________________ 5
MAX1549 Evaluation Kit Evaluates: MAX1549
Figure 2. MAX1549 EV Kit Component Placement Guide—Component Side
6
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MAX1549 Evaluation Kit Evaluates: MAX1549
Figure 3. MAX1549 EV Kit Component Placement Guide—Solder Side
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MAX1549 Evaluation Kit Evaluates: MAX1549
Figure 4. MAX1549 EV Kit PC Board Layout—Ground/Signal Layer 2
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MAX1549 Evaluation Kit Evaluates: MAX1549
Figure 5. MAX1549 EV Kit PC Board Layout—Ground Plane Layer 3
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MAX1549 Evaluation Kit Evaluates: MAX1549
Figure 6. MAX1549 EV Kit PC Board Layout—Component Side
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MAX1549 Evaluation Kit Evaluates: MAX1549
Figure 7. MAX1549 EV Kit PC Board Layout—Solder Side
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