MAXIM MAX1541EVKIT

19-2861; Rev 0; 7/03
MAX1541 Evaluation Kit
This EV kit is a fully assembled and tested circuit
board. It also allows the evaluation of other dynamically
adjustable output voltages in the 0.7V to 5.5V range by
changing resistors R9, R10, and R11 (OUT1) and other
fixed output voltages in the 0.7V to 5.5V range by
changing resistors R18 and R19 (OUT2).
Features
♦ 7V to 24V Input Voltage Range
♦ Dynamically Selectable Output Voltages 1.0V/1.5V
(OUT1, Adjustable from 0.7V to 5.5V)
♦ Fixed 2.5V/1.8V Output Voltage (OUT2, Adjustable
from 0.7V to 5.5V)
♦ Fixed 5V or Adjustable 100mA Linear Regulator
♦ 4A Output Current for Each Output
♦ 355kHz/485kHz Switching Frequency
(OUT2/OUT1, Respectively)
♦ Selectable Inductor Saturation Protection
♦ Separate Power-Good Outputs
♦ Selectable Overvoltage/Undervoltage Protection
♦ Low-Profile Components
♦ Fully Assembled and Tested
Ordering Information
PART
TEMP RANGE
MAX1541EVKIT
0°C to +70°C
IC PACKAGE
40 Thin QFN 6mm x 6mm
Component List
DESIGNATION
QTY
DESCRIPTION
C1, C2
2
10µF, 25V ceramic capacitors (1812)
Taiyo Yuden TMK432BJ106KM or
TDK C4532X5R1E106M
C3
1
470µF, 4V, 10mΩ low-ESR capacitor
Sanyo 4TPD470M
1
220µF, 4V, 15mΩ low-ESR capacitor
Sanyo 4TPE220MF
2
1µF ±20%, 10V X5R ceramic
capacitors (0805)
Taiyo Yuden LMK212BJ105KG or
TDK C2012X5R1A105M
3
C4
C5, C6
C7, C8, C14
C9
1
DESIGNATION
QTY
DESCRIPTION
1
0.22µF, 25V X5R ceramic capacitor
(0805)
Murata GRM219R71E224KC01D or
Taiyo Yuden EMK212BJ224KG
C11
1
1000pF ±10%, 50V C0G ceramic
capacitor (0603)
TDK1608X7R1H102K or
Murata GRM188R71H102K
C12, C13
2
470pF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H471K
0.1µF ±10%, 25V X7R ceramic
capacitors (0603)
Murata GRM188R71E104K or
TDK C1608X7R1E104K
C15
1
10µF, 10V tantalum capacitor (case B)
AVX TAJB10M010R
C16
1
3.3µF, 35V tantalum capacitor (case B)
AVX TAJB335M035R
47pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H470J
C17–C22
0
Not installed (0603)
D1, D2
2
100mA, 30V Schottky diodes
Central Semiconductor CMPSH-3
C10
________________________________________________________________ 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: MAX1541
General Description
The MAX1541 evaluation kit (EV kit) demonstrates the
MAX1541’s standard 4A application circuit. This DC-DC
converter steps down high-voltage batteries and/or AC
adapters, generating precision low-voltage GPU, DPR,
and chipset power supplies for notebook computers.
The MAX1541 EV kit provides a dynamically adjustable
1.0V/1.5V output voltage (OUT1), a fixed 2.5V output
voltage (OUT2), and a fixed 5V, 100mA linear regulator
(LDOOUT) from the 7V to 24V battery input range. It
delivers up to 4A output current for each output voltage
with greater than 90% efficiency. The EV kit operates at
355kHz/485kHz switching frequency (OUT2/OUT1,
respectively) and has superior line- and load-transient
response.
Evaluates: MAX1541
MAX1541 Evaluation Kit
Component List (continued)
DESIGNATION
QTY
DESCRIPTION
D3, D4
2
1A, 30V Schottky diodes
Nihon EP10QY03 or
Toshiba CRS02
JU1, JU2,
JU8, JU9
4
3-pin headers, 0.1 centers
JU3, JU6, JU7
3
4-pin headers, 0.1 centers
R11
1
150kΩ ±1% resistor (0603)
2
100kΩ ±1% resistors (0603)
R13, R15
2
49.9kΩ ±1% resistors (0603)
DESIGNATION
QTY
DESCRIPTION
R5, R16, R17,
R18, R22, R24,
R25, R31, R32,
R33, R35–R38
0
Not installed (0603)
R9, R10
2
75kΩ ±1% resistors (0603)
L1
1
1.8µH, 5.4A power inductor
Sumida CDEP105(L)-1R8
R12, R14
2
1
4.3µH, 6.8A power inductor
Sumida CDEP105(L)-4R3
R20, R21
L2
100kΩ ±5% resistors (0603)
R26
1
10Ω ±5% resistor (0805)
N1A, N1B, N2A,
N2B
Dual N-channel MOSFETs
Fairchild FDS6982A
R29, R30
0
Not installed (short PC trace) (0603)
2
U1
1
MAX1541ETL (40-pin QFN 6mm x 6mm)
R1
1
20Ω ±5% resistor (0805)
None
4
Rubber bumpers
None
7
Shunts, 0.1 centers
None
1
MAX1541 PC board
R2, R3
2
0.015Ω ±1%, 1/2W resistors (2010)
IRC LR2010-01-R015-F or
Dale WSL-2010-R015F
R4, R6, R7, R8,
R19, R23, R27,
R28, R34
9
0Ω resistors (0603)
Component Suppliers
SUPPLIER
PHONE
FAX
WEBSITE
AVX
843-946-0238
843-626-3123
www.avxcorp.com
Central Semiconductor
516-435-1110
516-435-1824
www.centralsemi.com
Dale-Vishay
402-564-3131
402-63-6296
www.vishay.com
Fairchild
408-721-2181
408-721-1635
www.fairchildsemi.com
IRC
361-992-7900
361-992-3377
www.irctt.com
Murata
770-436-1300
770-436-3636
www.murata.com
Nihon
847-843-7500
847-843-2798
www.niec.co.jp
Sanyo
619-661-6835
619-661-1055
www.sanyovideo.com
Sumida
708-956-0666
708-956-0702
www.sumida.com
Taiyo Yuden
800-348-2496
847-925-0899
www.t-yuden.com
TDK
847-390-4373
847-390-4428
www.component.tdk.com
Note: Please indicate that you are using the MAX1541 when contacting these component suppliers.
2
_______________________________________________________________________________________
MAX1541 Evaluation Kit
Equipment Needed
• 7V to 24V power supply, battery, or notebook AC
adapter
• Dummy loads capable of sinking 4A
• Digital multimeters (DMMs)
• 100MHz dual-trace oscilloscope
1) Ensure that the circuit is connected correctly to the
supplies and dummy load prior to applying any
power.
Table 2. Jumper JU2 Functions (Output
Voltage OUT2 Control)
JU2
ON2 PIN
OUT2
1 & 2 (default)
Connected to VCC.
OUT2 enabled,
VOUT2 = 2.5V.
2&3
Connected to GND.
OUT2 shutdown
mode.
Not installed
ON2 must be driven
by an external signal
connected to ON1
pad.
OUT2 operation
depends on the
external ON2 signal
levels.
2) Verify that the shunts are across:
a) JU1 pins 1 and 2 (ON1 high), JU2 pins 1 and 2
(ON2 high).
b) JU3 pins 1 and 2 (SKIP/high, forced PWM), JU6
pins 1 and 2 (OVP/UVP enabled).
c) JU7 pins 1 and 3 (TON = REF, 450kHz switching
frequency), JU8 pins 1 and 2 (GATE low, VOUT1 =
1.5V).
Table 3. Jumper JU3 Functions (LowNoise Mode)
JU3
SKIP PIN
OPERATIONAL
MODE
1 & 2 (default)
Connected to VCC.
Low-noise mode,
OUT1 and OUT2 are
in forced-PWM mode.
1&3
Connected to REF.
OUT1 is in pulseskipping mode;
OUT2 is in forcedPWM mode.
1&4
Connected to GND.
OUT1 and OUT2 are
in pulse-skipping
mode.
Open.
OUT1 is in forcedPWM mode; OUT2
is in pulse-skipping
mode.
d) JU9 pins 1 and 2 (linear regulator enabled)
3) Turn on VIN, input/battery power supply.
4) Verify that the output voltages are VOUT1 = 1.5V,
VOUT2 = 2.5V, and VLDOOUT = 5V.
Detailed Description
Jumper Settings
Table 1. Jumper JU1 Functions (Output
Voltage OUT1 Control)
JU1
ON1 PIN
OUT1
1 & 2 (default)
Connected to VCC.
OUT1 enabled,
VOUT1 = 1.5V.
2&3
Connected to GND.
OUT1 shutdown
mode.
Not installed
ON1 must be driven
by an external signal
connected to ON1
pad.
OUT1 operation
depends on the
external ON1 signal
levels.
Not installed
_______________________________________________________________________________________
3
Evaluates: MAX1541
Quick Start
Evaluates: MAX1541
MAX1541 Evaluation Kit
Table 4. Jumper JU6 Functions (Overvoltage/Undervoltage Protection Selection)
JU6
OVP/UVP PIN
UVP
1&2
(default)
Connected to VCC.
OVP/DISCHARGE MODE
UVP is enabled; UVP
OVP and discharge mode are enabled;
threshold is 70% of nominal. OVP threshold is 116% of nominal.
1&3
Connected to REF.
UVP is enabled.
OVP and discharge mode are disabled.
1&4
Connected to GND.
UVP is disabled.
OVP and discharge mode are disabled.
Not installed
Floating.
UVP is disabled.
OVP and discharge mode are enabled.
Note: The MAX1541 detects and latches the discharge-mode state set by OVP/UVP on startup.
Table 5. Jumper JU7 Functions
(Switching-Frequency Selection)
JU7
TON PIN
FREQUENCY
(OUT1/OUT2) (kHz)
JU9
LDOON PIN
1&2
Connected to VCC.
235/170
1 & 2 (default)
Connected to LDOIN
through JU5.
LDOOUT enabled,
VLDOOUT = 5V.
1&3
(default)
Connected to REF.
485/355
(as shipped)
2&3
Connected to GND.
Shutdown mode.
1&4
Connected to GND.
620/460
Not installed
Not
installed
Floating.
345/255
Note: Do not change the operating frequency without first
recalculating component values because 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 6. Jumper JU8 Functions (GATE)
JU8
1 & 2 (default)
2&3
Not installed
4
Table 7. Jumper JU9 Functions (Linear
Regulator LDOOUT Control)
GATE PIN
OUT1
A logic low on GATE
turns off the internal
MOSFET so that OD
Connected to GND.
appears as high
impedance, VOUT1 =
1.5V.
Connected to VCC.
GATE must be driven
by an external signal
connected to GATE
pad.
A logic high on GATE
turns on the internal
MOSFET, pulling OD to
ground, VOUT1 = 1.0V.
OUT1 voltage
depends on the
external GATE signal
levels.
LDOOUT
LDOON connected to R24 and R25 set the
voltage-divider
LDOIN undervoltage
R24/R25.
lockout threshold.
Evaluating Other Dynamic Output Voltages
(OUT1)
The EV kit output is preset to 1.0V/1.5V (OUT1), 2.5V
(OUT2), and 5V (LDOOUT). However, OUT1 can also
be adjusted between 0.7V and 2V (FB1 = OUT1) by
selecting R9, R10, and R11 values. The MAX1541 regulates FB1 to the voltage set at REFIN1. By changing the
voltage at REFIN1, the MAX1541 can be used in applications that require dynamic output-voltage changes
between two set points. Using the GATE signal and
open-drain output (OD), a resistor can be switched in
and out of the REFIN1 resistor-divider, changing the
voltage at REFIN1. A logic high on GATE turns on the
internal N-channel MOSFET, forcing OD to a lowimpedance state. A logic low on GATE disables the Nchannel MOSFET, so OD is high impedance. The two
output voltages (FB1 = OUT1) are determined by the
following equations:
VOUT1(LOW) = VREF(R10 / (R9 + R10))
VOUT1(HIGH) = VREF(R10 + R11) / (R9 + R10 + R11)
where VREF = 2.0V.
Refer to the MAX1540/MAX1541 data sheet for selection of output capacitor and inductor values for output
voltages greater than 2V.
_______________________________________________________________________________________
MAX1541 Evaluation Kit
Evaluating Other Linear-Regulator Output
Voltages (LDOOUT)
The MAX1541 provides a fixed 2.5V output (OUT2)
when FB2 is connected to GND (R18 = open, R19 = 0,
R38 = open) or fixed 1.8V output when FB2 is connected to VCC (R18 = open, R19 = open, R38 = 0).
OUT2 can also be adjusted from 0.7V to 5.5V by using
a resistive voltage-divider formed by R18 and R19 (R38
= open). The MAX1541 regulates FB2 to a fixed reference voltage (0.7V).
The adjusted output voltage is:
VOUT2 = VFB2(1 + R18 / R19)
where VFB2 = 0.7V.
The MAX1541 provides a fixed 5V linear-regulator output (LDOOUT) when LDOON is connected to VIN.
However, the linear output voltage can be adjusted
between 1.25V and 24V by selecting R22 and R23 values.
The adjusted linear output voltage is:
VLDOOUT = VFBLDO(1 + R22 / R23)
where VFBLDO = 1.25V.
Note: When LDOOUT is set to a voltage other than
+5V, cut the trace short across JU4 and connect a separate 5V source to VBIAS.
Refer to the MAX1540/MAX1541 data sheet for selection of output capacitor and inductor values for different
output voltages.
Note: Make sure LDOOUT capacitors C14 and C15
have the correct voltage rating to match the LDOOUT
voltage.
_______________________________________________________________________________________
5
Evaluates: MAX1541
Evaluating Other Fixed-Output Voltages
(OUT2)
6
GND
C3
470µF
4V
VOUT1 VOUT1
1.5V/1V
4A
VIN
24V MAX
GND
REF
450kHz
R2
0.015Ω
1%
Figure 1. MAX1541 EV Kit Schematic
_______________________________________________________________________________________
VCC
L1
1.8µH
3
4
2
D3
6
1
3
2
600kHz
R11
150kΩ
1%
JU8
R17
OPEN
R37
OPEN
R9
75kΩ
1%
REF
REF
3
C10
0.22µF
R15
49.9kΩ
1%
R14
100kΩ
1%
R35
OPEN
VCC
3
5
4
6
9
8
38
12
10
11
2
35
7
34
36
37
28
31
32
30
VCC
REF
SKIP
C9
47pF
C17
OPEN
R32
OPEN
JU3
1
C13
470pF
REF
R36
OPEN
REF
4
2
VCC
R29
SHORT
(PC TRACE)
R10
75kΩ
1%
C21
OPEN
R7
0Ω
R6
0Ω
C7
0.1µF
VCC
VCC
JU7
1 FLOAT = 300kHz
GATE
R13
49.9kΩ
1%
REF
R8
0Ω
N1-A
2
4
C20
OPEN
7
5
D1
CMPSH-3
C11
1000pF
R12
100kΩ
1%
R5
OPEN
R4
0Ω
1
8
3
N1-B
VOUT1
VCC
200kHz
C12
470pF
R16
OPEN
C1
10µF
25V
VIN
VDD
R31
R33 OPEN
OPEN
C6
1µF
10V
U1
23
V+
TON
GATE
ILIM2
ILIM1
FBLANK
OD
REF
REFIN1
SKIP
FB1
CC1
OUT1
CSN1
CSP1
DL1
OVP/UVP
FB2
ON2
ON1
PGOOD2
PGOOD1
FBLDO
LDOOUT
OUT2
LDOON
LDOIN
CSN2
CSP2
GND
LX1
LX2
DH2
BST2
VIN
DL2
MAX1541
VDD
25
VDD
DH1
BST1
LSAT
VCC
R1
20Ω
1
15
39
40
17
33
27
26
16
29
24
14
13
21
22
19
18
C22
OPEN
R38
OPEN
R21
100kΩ
R20
100kΩ
C19
OPEN
R34
0Ω
C16
3.3µF
35V
R19
0Ω
VCC
VCC
VCC
R22
OPEN
3
1
1
JU6
4
2
VCC
R18
OPEN
PGOOD2
3
R27
0Ω
N2-A
2
N2-B
4
C5
1µF
10V
R23
0Ω
2
PGOOD1
JU9
C18
OPEN
R26
10Ω
C8
0.1µF
VOUT2
R30
D2
SHORT
CMPSH-3
20 (PC TRACE)
JU1
C14
0.1µF
REF
VOUT2
3
1
2
VCC
R25
OPEN
ON1
3
1
2 JU2
ON2
LDOOUT
VIN
LDOIN
VOUT2
VBIAS
LDOOUT
R3
0.015Ω
1%
VCC
JU5
JU4
C15
10µF
10V
LDOOUT
D4
L2
4.3µH
C2
10µF
25V
LDOON
N
8
N
6
R28
0Ω
1
R24
OPEN
7
3
5
VIN
GND
C4
220µF
4V
VOUT2
2.5V
4A
Evaluates: MAX1541
MAX1541 Evaluation Kit
MAX1541 Evaluation Kit
Evaluates: MAX1541
Figure 2. MAX1541EV Kit Component Placement Guide—Top
Silkscreen
Figure 3. MAX1541 EV Kit Component Placement Guide—
Bottom Silkscreen
Figure 4. MAX1541 EV Kit PC Board Layout—Component Side
Figure 5. MAX1541 EV Kit PC Board Layout—Ground Layer 2
_______________________________________________________________________________________
7
Evaluates: MAX1541
MAX1541 Evaluation Kit
Figure 6. MAX1541 EV Kit PC Board Layout—Ground Layer 3
Figure 7. MAX1541 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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.