19-3520; Rev 0; 11/04
MAX1531 Evaluation Kit
Features
The MAX1531 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that provides
logic and bias power required for liquid crystal display
(LCD) monitors. The EV kit contains a step-down
switching regulator, a logic-supply linear regulator, a
source-driver-supply linear regulator, a gamma-reference linear regulator, a two-stage positive charge
pump and linear regulator for the TFT gate-on supply,
and a one-stage negative charge pump and linear regulator for the TFT gate-off supply. The source-driver
supply, the gamma-reference supply, the gate-on supply, and the gate-off supply can be sequenced in any
power-up order. The EV kit also includes a MAX1522
step-up switching regulator to provide a higher output
voltage option for the source-driver supply and the
gamma reference.
The EV kit produces the output voltages listed in the
features column using a +10.5V to +24V input voltage
range. The input range can be reduced to +9.5V if the
included MAX1522 step-up regulator circuit is used. If
lower output voltages are acceptable, the input range
can be further reduced to +8V.
The EV kit features undervoltage protection for the
input, overcurrent protection for the step-down switching regulator, and overload protection for the sourcedrive linear regulator. Operation at 500kHz allows the
use of small surface-mount components. The EV kit
also evaluates the MAX1530.
♦ Output Voltages (Input Range = +10.5V to +24V or
+9.5V to +24V Using Included MAX1522 Circuit)
+3.3V Output at 1.5A (Step-Down Switching
Regulator)
+2.5V Output at 500mA (Logic-Supply
Regulator)
+10V Output at 500mA (Source-Driver Supply
Regulator)
+9.7V Output at 50mA (Gamma-Reference
Regulator)
+25V Output at 25mA (Positive Charge Pump
and Linear Regulator)
-9V Output at 50mA (Negative Charge Pump
and Linear Regulator)
Component List
DESCRIPTION
♦ +8V to +24V Input Range (Reduced Output
Voltages)
♦ Resistor-Adjustable Outputs
♦ 92% Efficiency (Step-Down Switching Regulator)
♦ 250kHz/500kHz Selectable Step-Down Switching
Frequency
♦ Programmable Power-Up Sequencing
♦ Soft-Start for All Outputs
♦ Multilevel Protection
Resistor-Adjustable Input Undervoltage
Threshold
Output Undervoltage Shutdown
Overcurrent Protection for One Linear
Regulator
Current Limit for the Step-Down Switching
Regulator
♦ External Step-Up Switching Regulator (MAX1522)
Included
DESIGNATION
QTY
C1, C4
2
1µF ±10%, 25V X7R ceramic
capacitors (0805)
TDK C2012X7R1E105K
♦ Also Evaluates the MAX1530 (IC Replacement
Required)
C2, C23
0
Not installed capacitors (0603)
♦ Fully Assembled and Tested
C3
1
4.7µF ±10%, 25V X7R ceramic
capacitor (1210)
TDK C3225X7R1E475K
C5, C6, C8,
C11, C14, C15,
C17, C18, C20
9
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H104K
C7
1
22µF ±20%, 6.3V X7R ceramic
capacitor (1206)
TDK C3216X7R0J226M
♦ Low-Profile, Surface-Mount Components
Ordering Information
PART
TEMP RANGE
IC PACKAGE
MAX1531EVKIT
0°C to +70°C
32 TQFN (5mm x 5mm)
________________________________________________________________ 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: MAX1530/MAX1531
General Description
Evaluates: MAX1530/MAX1531
MAX1531 Evaluation Kit
Component List (continued)
DESIGNATION
C9
C10
C12, C19
C13, C25
C16
C21, C22
C24
C26
D1, D6
D2
D3, D4, D5
D7
2
QTY
DESCRIPTION
1
10µF ±20%, 6.3V X5R ceramic
capacitor (1206)
TDK C3216X5R0J106M
1
470pF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H471K
2
0.47µF ±10%, 16V X7R ceramic
capacitors (0805)
TDK C2012X7R1C474K
DESIGNATION
QTY
DESCRIPTION
L1
1
10µH, 2.3ADC inductor
Sumida CDR7D28MN-100
L2
1
22µH, 0.90ADC inductor
Sumida CDRH5D28-220
N1
1
2.5A, 30V dual n-channel MOSFET
(Super SOT-6)
Fairchild Semiconductor FDC6561AN
N2
1
5.2A, 30V n-channel MOSFET (Super
SOT-6)
Fairchild Semiconductor FDC633N
Q1, Q4
2
3A, 60V low-saturation pnp bipolar
transistors
(SOT-223)
Fairchild Semiconductor NZT660A
2
4.7µF ±10%, 16V X7R ceramic
capacitors (1206)
TDK C3216X7R1C475K
1
0.47µF ±20%, 50V X7R ceramic
capacitor (1210)
TDK C3225X7R1H474M
Q2, Q3
2
2
2.2µF ±10%, 25V X7R ceramic
capacitors (1206)
TDK C3216X7R1E225K
200mA, 40V pnp bipolar transistors
(SOT23)
Central Semiconductor CMPT3906
10µF ±20%, 25V X5R ceramic
capacitor (1210)
TDK C3225X5R1E106M
Q5, Q6
2
200mA, 40V npn bipolar transistors
(SOT23)
Central Semiconductor CMPT3904
R1
1
17.8kΩ ±1% resistor (0805)
1µF ±10%, 10V X5R ceramic
capacitor (0603)
TDK C1608X5R1A105K
R2, R23
2
10.7kΩ ±1% resistors (0805)
R3
1
124kΩ ±1% resistor (0805)
1
1
2
100mA, 30V Schottky diodes (SOD523)
Central Semiconductor CMOSH-3
1
1A, 30V Schottky diode (S-flat)
Toshiba CRS02
3
250mA, 100V dual diodes (SOT23)
Central Semiconductor CMPD6001S
1
250mA, 75V high-speed silicon diode
(SOD-523)
Central Semiconductor CMOD4448
R4
1
20.0kΩ ±1% resistor (0805)
R5, R6, R7,
R11
4
100kΩ ±5% resistors (0805)
R8, R17, R24,
R27
4
6.8kΩ ±5% resistors (0805)
R9, R10, R19,
R32
4
10.0kΩ ±1% resistors (0805)
R12
1
301kΩ ±1% resistor (0805)
R13
1
221kΩ ±1% resistor (0805)
121kΩ ±1% resistor (0805)
R14
1
R15, R18
2
68.1kΩ ±1% resistors (0805)
R16
1
43.2kΩ ±1% resistor (0805)
JU1,
JU12–JU16
6
3-pin headers
R21
1
1.5kΩ ±5% resistor (0805)
JU2, JU3
2
2-pin headers
R22
1
75.0kΩ ±1% resistor (0805)
JU4–JU7
4
3-way jumpers (4 pins)
R25
1
200kΩ ±1% resistor (0805)
JU8–JU11
4
4-way jumpers (5 pins)
R26
1
10.5kΩ ±1% resistor (0805)
_______________________________________________________________________________________
MAX1531 Evaluation Kit
DESIGNATION
QTY
R28
1
DESCRIPTION
90.9kΩ ±1% resistor (0805)
R29
1
48.7kΩ ±1% resistor (0805)
R30
1
1Ω ±5% resistor (0805)
R31
1
110kΩ ±1% resistor (0805)
R33
1
0.050Ω ±1% resistor (1206)
IRC LRC-LR 1206-01-R050-F
R34
0
Not installed resistor (0805)
R35, R36
2
1.00Ω ±1% resistors (0805)
R37, R38
2
10Ω ±5% resistors (0805)
R39–R42
4
2.0kΩ ±5% resistors (0805)
U1
1
MAX1531ETJ (32-pin TQFN)
U2
1
MAX1522EUT-T (6-pin SOT23)
None
16
Shunts (see table for jumper settings)
None
1
MAX1531 PC board
Quick Start
The MAX1531 EV kit is fully assembled and tested.
Follow these steps to verify board operation. Do not
turn on the power supply until all connections are
completed.
The MAX1531 EV kit operates with up to +24V inputs.
However, due to external-component voltage stress limitations, default jumper configurations must be modified
for operation above +13.2V. See the Positive Charge
Pump and Gate-On Linear Regulator Output Voltage
(GON) sections.
Recommended Equipment
• +10.5V to +13.2V, 2A DC power supply
• One voltmeter
1) Verify that a shunt is across pins 1 and 2 of jumpers
JU1, JU10, and JU12.
2) Verify that there are no shunts across jumpers JU2
and JU3.
3) Verify that a shunt is across pins 1 and 3 of jumpers
JU4, JU5, JU6, JU7, and JU8.
4) Verify that a shunt is across pins 1 and 5 of jumper
JU9.
5) Verify that a shunt is across pins 1 and 4 of jumper
JU11.
6) Verify that a shunt is across pins 2 and 3 of jumpers
JU13, JU14, JU15, and JU16.
7) Connect the positive terminal of the input power
supply to the PIN pad. Connect the negative terminal of the input power supply to the PGND pad.
8) Turn on the power supply and verify that the stepdown regulator output (VOUT) is +3.3V.
9) Verify that the internal 5V linear regulator output
(VL) is +5V.
10) Verify that the logic-supply linear regulator output
(VLOG) is +2.5V.
11) Verify that the source-driver-supply linear regulator
output (VSRC) is +10V.
12) Verify that the gamma-reference linear regulator
output (VGAM) is +9.7V.
13) Verify that the gate-on linear regulator output (GON)
is +25V.
14) Verify that the gate-off linear regulator output
(GOFF) is -9V.
For instructions on selecting the feedback resistors for
other output voltages, see the Output Voltage Selection
section.
Detailed Description
The MAX1531 EV kit contains a step-down switching
regulator, a linear regulator for a low-voltage logic supply, a high-current linear regulator for a source-driver
supply, a linear regulator for a gamma reference, a twostage positive charge pump with a positive high-voltage linear regulator, and a one-stage negative charge
pump with a negative linear regulator. The EV kit operates from a +10.5V and +24V DC power supply, which
Component Suppliers
PHONE
FAX
Central Semiconductor
SUPPLIER
631-435-1110
631-435-1824
www.centralsemi.com
WEBSITE
Fairchild
888-522-5372
—
www.fairchildsemi.com
IRC
361-992-7900
361-992-3377
www.irctt.com
Sumida
847-545-6700
847-545-6720
www.sumida.com
TDK
847-803-6100
847-390-4405
www.component.tdk.com
Toshiba
949-455-2000
949-859-3963
www.toshiba.com/taec
Note: Indicate you are using the MAX1530/MAX1531 when contacting these manufacturers.
_______________________________________________________________________________________
3
Evaluates: MAX1530/MAX1531
Component List (continued)
Evaluates: MAX1530/MAX1531
MAX1531 Evaluation Kit
can provide at least 2A. The step-down switching regulator’s switching frequency is jumper configurable
between 250kHz and 500kHz. The adjustable input
undervoltage protection (EN) protects the EV kit from
undervoltage conditions. The step-up switching regulator and the source-drive regulator are protected against
overloads.
The step-down switching regulator (VOUT) generates a
+3.3V output and can provide at least 1.5A. The stepdown switching-regulator output voltage can be adjusted as low as +1.24V using different feedback resistors
(see the Output Voltage Selection section).
The logic voltage supply (VLOG) is set to +2.5V using a
linear regulator controller and an external pnp bipolar
pass transistor. This logic voltage supply can provide at
least 500mA of current. The logic-voltage-supply linear
regulator’s output can be adjusted between +1.24V and
its input supply, which is the step-down regulator’s output voltage (see the Output Voltage Selection section).
The source-driver supply (VSRC) is set to +10V using a
linear regulator controller and an external pnp bipolar
pass transistor. This source-driver supply can provide
at least 500mA of current. The source-drive linear regulator’s output can be adjusted between +1.24V and its
input voltage, which is either the EV kit input voltage
(PIN) or the output of the MAX1522 step-up regulator,
depending on jumper JU15 (see the Output Voltage
Selection section).
The gamma reference (VGAM) is set to +9.7V using a linear regulator controller and an external pnp bipolar pass
transistor. This gamma reference can provide at least
50mA of current. The gamma linear regulator’s output
can be adjusted between +1.24V and its input voltage,
which is either the EV kit input voltage (PIN) or the output
of the MAX1522 step-up regulator, depending on jumper
JU14 (see the Output Voltage Selection section).
The TFT gate-on supply (GON) uses a two-stage positive charge pump to generate approximately +33V. The
output is postregulated to +25V using a linear regulator
controller and an external pnp bipolar pass transistor
and can provide at least 25mA. The positive linear regulator’s output can be adjusted between +1.24V and its
input, which depends on the EV kit’s input voltage and
the charge-pump configuration, jumpers JU12 and
JU13 (see the Output Voltage Selection section).
The TFT gate-off supply (GOFF) uses a negative charge
pump to generate approximately -11V. The output is
postregulated to -9V using a linear regulator controller
and an external npn bipolar pass transistor and can provide greater than 50mA. The negative linear regulator’s
output can be adjusted between 0V and its input volt4
age, which is the output of the negative charge pump
(see the Output Voltage Selection section).
The EV kit also features power-up sequencing. After EN
and SEQ go high, the logic voltage supply (VLOG) softstarts. The gamma reference, the gate-on supply, the
source-driver supply, and the gate-off supply can softstart in any sequence by setting the appropriate
jumpers (see the Power-Up Sequencing section).
The EV kit includes a current-limit circuit for the stepdown switching regulator. The current-limit threshold is
set by resistor-dividers R12, R13, and the RDS(on) of
MOSFET N1 (refer to the MOSFET Selection and
Current-Limit Setting section in the MAX1531 data sheet
for further detail). The EV kit also includes current overload protection for the source-driver supply voltage. The
MAX1531 will shut down if the source-driver supply
exceeds a current threshold. The output current overload threshold is set by sense resistors R35 and R36
(refer to the Overcurrent Protection Block (CSH, CSL)
section in the MAX1531 data sheet for further detail).
Jumper Selection
Enable (EN)
The MAX1531 features an enable (EN) pin that enables
or disables the MAX1531 and the EV kit’s output. The
EN pin can also be used with resistor-dividers R3 and
R4 to set the lower limit of the input voltage range (refer
to the On/Off Control (EN) section in the MAX1531 data
sheet for further detail). The 3-pin jumper JU1 provides
an option to enable, disable, or use the undervoltage
threshold feature for the MAX1531 EV kit. Table 1 lists
the selectable jumper options.
Table 1. Jumper JU1 Functions
SHUNT
LOCATION
EN PIN
MAX1531 (U1)
IC STATUS
None
Connected to GND
Disabled
1-2
(Default)
Connected to PIN
through resistordividers R3 and R4
Enabled
when VPIN > 9V
2-3
Connected to VL
Enabled
Switching Frequency Selection (FREQ)
The MAX1531 EV kit features an option to choose the
step-down switching regulator’s operating frequency
(JU2). Table 2 lists the selectable jumper options. The
EV kit is configured for 500kHz operation. Optimum
performance at 250kHz requires a larger inductor value
(refer to the Inductor Selection section in the MAX1531
data sheet).
_______________________________________________________________________________________
MAX1531 Evaluation Kit
Table 3. Jumper JU3 Function
SHUNT
LOCATION
FREQ PIN
MAX1531 EV KIT
FREQUENCY
Installed
Connected to GND
Frequency = 250kHz
None
(Default)
Connected to VL
through R5
Frequency = 500kHz
SHUNT
LOCATION
SEQ PIN
MAX1531 STATE
Installed
Connected to
GND
Sequence block disabled.
VSRC, VGAM, GON, and
GOFF disabled, regardless of
ONL2 to ONL5 voltage levels.
None
(Default)
Sequence block enabled.
Each ONL_ sources 2µA.
VGAM soft-starts when ONL2
reaches 1.24V.
Connected to GON soft-starts when ONL3
VL through R6 reaches 1.24V.
VSRC soft-starts when ONL4
reaches 1.24V.
GOFF soft-starts when ONL5
reaches 1.24V
Power-Up Sequencing (SEQ)
The EV kit features adjustable power-up sequencing for
several of the linear regulators. After the MAX1531’s EN
pin goes high, the internal VL linear regulator starts up
and the step-down switching regulator soft-starts.
When the step-down regulator reaches regulation, the
logic-voltage-supply linear regulator (VLOG) and the
sequence block that controls the other four linear regulators are simultaneously enabled. The logic regulator
soft-starts immediately but the sequence block starts
only if SEQ is high. SEQ is controlled by JU3.
Each linear regulator soft-starts individually when it is
enabled. After SEQ goes high, the ONL2 to ONL5 pins
each source current into C11, which controls the overall
time for startup. Resistors R14, R15, and R16 determine
the startup spacing between the respective regulator
and JU8 to JU11 determine the startup order. Each
regulator starts after SEQ is high and its ONL_ pin
exceeds 1.24V. JU4 to JU7 enable immediate startup
of their respective regulator after the step-down regulator reaches regulation and SEQ is high, without additional delay. (See the Power-Up Sequencing section.)
See Tables 3 through 7 for configuring the jumpers.
Table 4. ONL2 Setting (JU4 and JU8)
JU4 SHUNT
LOCATION
JU8 SHUNT
LOCATION
ONL2 PIN
1-2
Don’t Care
Connected to VL
through R39
1-4
Don’t Care
Connected to
GND
1-2
1-3
(Default)
SEQUENCING MODE
Gamma linear regulator enabled immediately if JU3 is removed
(SEQ = high) and step-down switching regulator soft-start is
finished. Sequence not used.
Gamma linear regulator disabled.
Connected to R14
Gamma linear regulator soft-starts about 6ms after sequence
block enabled.
1-3
(Default)
Connected to R15
Gamma linear regulator soft-starts about 9ms after sequence
block enabled.
1-4
Connected to R16
Gamma linear regulator soft-starts about 12ms after sequence
block enabled.
1-5
Connected to C11
Gamma linear regulator soft-starts about 15ms after sequence
block enabled.
_______________________________________________________________________________________
5
Evaluates: MAX1530/MAX1531
Table 2. Jumper JU2 Functions
Evaluates: MAX1530/MAX1531
MAX1531 Evaluation Kit
Table 5. ONL3 Setting (JU5 and JU9)
JU5 SHUNT
LOCATION
JU9 SHUNT
LOCATION
ONL3 PIN
1-2
Don’t Care
Connected to VL
through R40
1-4
Don’t Care
Connected to
GND
1-2
Connected to R14
GON linear regulator soft-starts about 6ms after sequence block
enabled.
1-3
Connected to R15
GON linear regulator soft-starts about 9ms after sequence block
enabled.
1-4
Connected to R16
GON linear regulator soft-starts about 12ms after sequence block
enabled.
1-5
(Default)
Connected to C11
GON linear regulator soft-starts about 15ms after sequence block
enabled.
1-3
(Default)
SEQUENCING MODE
GON linear regulator enabled immediately if JU3 is removed
(SEQ = high) and step-down switching regulator soft-start is
finished. Sequence not used.
GON linear regulator disabled.
Table 6. ONL4 Setting (JU6 and JU10)
JU6 SHUNT
LOCATION
JU10 SHUNT
LOCATION
ONL4 PIN
1-2
Don’t Care
Connected to VL
through R41
1-4
Don’t Care
Connected to
GND
1-2
(Default)
Connected to R14
VSRC linear regulator soft-starts about 6ms after sequence block
enabled.
1-3
Connected to R15
VSRC linear regulator soft-starts about 9ms after sequence block
enabled.
1-4
Connected to R16
VSRC linear regulator soft-starts about 12ms after sequence
block enabled.
1-5
Connected to C11
VSRC linear regulator soft-starts about 15ms after sequence
block enabled.
1-3
(Default)
6
SEQUENCING MODE
VSRC linear regulator enabled immediately if JU3 is removed
(SEQ = high) and step-down switching regulator soft-start is
finished. Sequence not used.
VSRC linear regulator disabled.
_______________________________________________________________________________________
MAX1531 Evaluation Kit
JU7 SHUNT
LOCATION
JU11 SHUNT
LOCATION
ONL5 PIN
1-2
Don’t Care
Connected to VL
through R42
1-4
Don’t Care
Connected to
GND
1-2
Connected to R14
GOFF linear regulator soft-starts about 6ms after sequence block
enabled.
1-3
Connected to R15
GOFF linear regulator soft-starts about 9ms after sequence block
enabled.
1-4
(Default)
Connected to R16
GOFF linear regulator soft-starts about 12ms after sequence
block enabled.
1-5
Connected to C11
GOFF linear regulator soft-starts about 15ms after sequence
block enabled.
1-3
(Default)
Positive Charge Pump
The positive charge pump of the MAX1531 EV kit powers the GON linear regulator and features an option to
cascade up to two charge-pump stages. The charge
pump’s first stage can be connected to PIN or VOUT,
and the charge pump’s second stage can be connected to PIN or the previous stage. Jumpers JU12 and
JU13 configure the number of stages and select the
voltage source for the positive charge pump on the
MAX1531 EV kit. Tables 8 and 9 list the jumper options.
The default configuration of the positive charge pump
of the MAX1531 EV kit is a two-stage charge pump
powered from PIN as indicated in Tables 8 and 9.
Since the positive charge pump powers the GON linear
regulator, ensure that the combination of the chargepump configuration and the input voltage range (PIN)
does not over stress the GON linear regulator’s external
pass transistor. The V CEO maximum rating of the
MMBT3904 used on this EV kit is 40V. If the input voltage (PIN) exceeds +13.2V, either reconfigure the
charge pump (using JU12 and JU13) as a two-stage
charge pump from VOUT or a one-stage charge pump
from PIN, as appropriate, or select a higher-voltagerated transistor for Q3. Also, if higher charge-pump
voltages are required, ensure that Q6 and C15 are not
over stressed. Refer to the Charge Pumps section of
the MAX1531 data sheet for more information on selecting a charge-pump configuration.
SEQUENCING MODE
GOFF linear regulator enabled immediately if JU3 is removed
(SEQ = high) and step-down switching regulator soft-start is
finished. Sequence not used.
GOFF linear regulator disabled.
Table 8. Jumper JU12 Functions
SHUNT
LOCATION
1ST STAGE
POSITIVE
CHARGE
PUMP
1-2
(Default)
Connected to
PIN
First stage of a two-stage
charge pump connected to
PIN.
2-3
Connected to
VOUT
First stage of a two-stage
charge pump connected to
VOUT.
None
Not used
OPERATING MODE
The first stage is not used for
one-stage charge pumps.
Table 9. Jumper JU13 Functions
SHUNT
LOCATION
2ND STAGE
POSITIVE
CHARGE
PUMP
1-2
Connected to
PIN
2-3
(Default)
None
OPERATING MODE
One-stage charge pump
connected to PIN.
Connected to
previous stage Last stage of a two-stage
charge-pump charge pump.
output
Not used
Charge pump not used.
_______________________________________________________________________________________
7
Evaluates: MAX1530/MAX1531
Table 7. ONL5 Setting (JU7 and JU11)
Evaluates: MAX1530/MAX1531
MAX1531 Evaluation Kit
VGAM Power Supply
The power supply for the VGAM linear regulator can be
connected to PIN or STEP_UP. PIN is the input voltage
for the EV kit. STEP_UP is the output of the MAX1522
step-up switching regulator circuit on the EV kit.
Jumper JU14 selects the power supply for the VGAM
linear regulator on the MAX1531 EV kit. Table 10 lists
the jumper options.
Table 12. Jumper JU16 Functions
SHUNT
LOCATION
MAX1522
SHDN PIN
MAX1522
OPERATING MODE
1-2
Connected to
VOUT
Enabled
2-3
(Default)
Connected to
GND
Disabled
Table 10. Jumper JU14 Functions
SHUNT
LOCATION
VGAM
POWER
SUPPLY
1-2
Connected to
STEP_UP
VGAM powered from the
output of the MAX1522 stepup regulator.
2-3
(Default)
Connected to
PIN
VGAM powered from PIN.
None
Not used
OPERATING MODE
VGAM not used.
VSRC Power Supply
The power supply for the VSRC linear regulator can be
connected to PIN or STEP_UP. PIN is the input voltage
for the EV kit. STEP_UP is the output of the MAX1522
step-up switching regulator circuit on the EV kit.
Jumper JU15 selects the power supply for the VSRC
linear regulator on the MAX1531 EV kit. Table 11 lists
the jumper options.
Table 11. Jumper JU15 Functions
SHUNT
LOCATION
VSRC
POWER
SUPPLY
1-2
Connected to
STEP_UP
VSRC powered from the
output of the MAX1522 stepup regulator.
2-3
(Default)
Connected to
PIN
VSRC powered from PIN.
None
Not used
OPERATING MODE
VSRC not used.
The MAX1522 Step-Up Circuit
The MAX1531 EV kit includes a MAX1522 step-up
switching regulator. This regulator is not generally
needed, but is provided as a convenience for applications where the input voltage (PIN) can be less than
VSRC. If the step-up is needed, enable the MAX1522
8
using JU16 and set JU14 and JU15 so that VGAM and
VSRC use the step-up’s output.
Output Voltage Selection
Step-Down Switching-Regulator Output
Voltage (VOUT)
The MAX1531 EV kit’s step-down switching-regulator
output (VOUT) is set to +3.3V by feedback resistors R1
and R2. To generate output voltages other than +3.3V
(from +1.24V up to 0.6 x VPIN), select different external
voltage-divider resistors (R1, R2). Output capacitor C7
is rated to +6.3V. To set the output voltage greater than
+6.3V, use a higher-voltage-rated capacitor. Refer to
the Main Step-Down Regulator Output Voltage
Selection section in the MAX1531 data sheet for
instructions on selecting the resistors.
Logic-Voltage-Supply Linear Regulator
Output Voltage (VLOG)
The MAX1531 EV kit’s logic-voltage-supply linear regulator output (VLOG) is set to +2.5V by feedback resistors R9 and R10. To generate output voltages other
than +2.5V (from +1.24V up to VOUT) select different
external voltage-divider resistors (R9, R10). Output
capacitor C9 is rated to +6.3V. To set the output voltage greater than +6.3V, use a higher-voltage-rated
capacitor. Refer to the Linear-Regulator Controllers
Output Voltage Selection section in the MAX1531 data
sheet for instructions on selecting the resistors.
Gamma-Reference Linear Regulator
Output Voltage (VGAM)
The MAX1531 EV kit’s gamma-reference linear regulator output (VGAM) is set to +9.7V by feedback resistors
R18 and R19. To generate output voltages other than
+9.7V (from +1.24V up to its input voltage) select different external voltage-divider resistors (R18, R19). Output
capacitor C12 is rated to +16V. To set the output voltage greater than +16V, use a higher-voltage-rated
capacitor. Refer to the Linear-Regulator Controllers
Output Voltage Selection section in the MAX1531 data
sheet for instructions on selecting the resistors.
_______________________________________________________________________________________
MAX1531 Evaluation Kit
Source-Supply Linear Regulator Output
Voltage (VSRC)
The MAX1531 EV kit’s gate-on linear regulator output
(GON) is set to +25V by feedback resistors R25 and
R26. To generate output voltages other than +25V (from
+1.24V up to the linear regulator’s input, which is the
output of the positive charge pump), select different
external voltage-divider resistors (R25, R26). Take care
not to exceed either the pnp pass transistor’s VCEO rating (40V) or the output capacitor’s (C16) +50V rating.
The MAX1531 EV kit’s source-supply linear regulator
output (VSRC) is set to +10V by feedback resistors R22
and R23. To generate output voltages other than +10V
(from +1.24V up to its input voltage) select different
external voltage-divider resistors (R22, R23). Output
capacitor C13 is rated to +16V. To set the output voltage greater than +16V, use a higher-voltage-rated
capacitor. Refer to the Linear-Regulator Controllers
Output Voltage Selection section in the MAX1531 data
sheet for instructions on selecting the resistors.
Before GON is enabled, Q3 is off and the positive
charge pump’s full output voltage is present across Q3.
If the input voltage (PIN) exceeds 13.2V, do not power
the EV kit with the charge pump configured as a twostage charge pump powered from PIN, as Q3’s 40V
rating will be exceeded. Configure JU12 and JU13 for a
two-stage charge pump powered from VOUT or as a
one-stage charge pump powered from PIN, whichever
is appropriate. Alternatively, select a different transistor
for Q3 and possibly Q6, which must withstand the
same voltage, minus VPIN. If VPIN exceeds +20V, even
a one-stage charge pump will exceed +40V, so either
change Q3 or disable the charge pump entirely and
power the linear regulator directly from PIN, whichever
is appropriate.
Refer to the Linear-Regulator Controllers Output
Voltage Selection section in the MAX1531 data sheet
for instruction on selecting the voltage-divider resistors.
Also, refer to the Charge Pumps section for more information about configuring the positive charge pump.
Gate-Off Linear Regulator Output
Voltage (GOFF)
The MAX1531 EV kit’s negative linear regulator output
(GOFF) is set to -9V by feedback resistors R28 and
R29. To generate output voltages other than -9V (0V
down to its input voltage), select different external voltage-divider resistors (R28, R29). Output capacitor C19
is rated to -16V. To set the output voltage below -16V,
use a higher-voltage-rated capacitor. Refer to the
Linear-Regulator Controllers Output Voltage Selection
and Charge Pumps sections in the MAX1531 data
sheet for instructions on selecting the resistors.
Evaluating the MAX1530
The MAX1531 EV kit can also evaluate the MAX1530.
To evaluate the MAX1530, replace U1 with the
MAX1530. Refer to the MAX1530/MAX1531 data sheets
for additional information.
_______________________________________________________________________________________
9
Evaluates: MAX1530/MAX1531
Gate-On Linear Regulator Output
Voltage (GON)
10
C11
0.1µF
R16
43.2kΩ
1%
R15
68.1kΩ
1%
R14
121kΩ
1%
4
5 1
3
5 1
3
STEP_UP
PIN
2
2
2
2
4
3
4
JU7
3
1
2
1
JU5 2
GND
Q4
3
Figure 1. MAX1531 EV Kit Schematic—Sheet 1 of 2
______________________________________________________________________________________
GND
3
3
4
JU6
4
2
1
2
R21
1.5kΩ
C13
R22
4.7µF 75kΩ
16V
1%
1
R35
1Ω
1%
R36
1Ω
1%
2
1
19
18
17
16
R23
10.7kΩ
1%
7
8
5
6
R19
10kΩ
1%
STEP_UP JU15
1
3 PIN
2
25
12
26
C4
1µF
JU4
1
R18
C12 68.1kΩ
0.47µF 1%
Q2
R17
1 6.8kΩ
R41
2kΩ
3
R7
100kΩ
R39
VL 2kΩ
C20 2
0.1µF
VL
VL
VSRC
+10V AT 500mA 2
C21
2.2µF
STEP_UP
VL
RESET
R6
100kΩ
R42
2kΩ
R40
2kΩ
JU3
3
VGAM
2
9.7V AT 50mA
JU14
1
5 1
JU11 3
4
5 1
JU10 3
4
4
JU9
JU8
R5
100kΩ
JU2
+5V
VL
FBL4
DRV4
CSH
CSL
FBL2
DRV2
ONL5
ONL4
ONL3
ONL2
FREQ
SEQ
RESET
2
U1
EN
30
3
MAX1531
VL
28
R4
20.0kΩ
1%
VL
JU1
1
DL
LX
DH
IN
13
31
32
20
29
21
22
23
27
FBL5
DRV5
ILIM
FBL3
DRV3
9
VL
10
15
3
4
11
RSTIN
14
FB
COMP
FBL1
DRV1
PGND
AGND
BST
24
R37
10Ω
D1
R3
124kΩ
1%
2
1
LX
2
IN
C17
0.1µF
1
C23
OPEN
R25
200kΩ
1%
R28
R29 90.9kΩ
48.7kΩ 1%
1%
3
D7
5
3
4
N1-A
2
3
2
C19
0.47µF
GOFF
C18
0.1µF
3
Q3
1
VLOG
Q1
C7
22µF
6.3V
C22
2.2µF
GND
PIN
GND
R13
221kΩ
1%
R12
301kΩ
1%
VL
+25V AT 25mA
-9V AT 50mA
GND
GON
C15
0.1µF
GND
2.5V AT 500mA
2
3
C3
4.7µF
25V
R8
N1-B 6.8kΩ
R24
6.8kΩ 2
C16
0.47µF
50V
D6
Q5
R27
6.8kΩ
1
PIN
L1
10µH
R9
R10
C9
10kΩ 10kΩ 10µF
1%
1%
6.3V
6
R34
OPEN
2
1
IN
C10
470pF
R38
10Ω
1
LX
R30
1Ω
LX
Q6 3
D5
R26
10.5kΩ
1%
R11
100kΩ
C1
1µF
C5
0.1µF
VL
2
LX
2 1
1
2
JU13 3
PIN
1 JU12
C6
0.1µF
PIN
R2
10.7kΩ
1%
3
R1
17.8kΩ
1%
D4 3
C2
OPEN
C14
0.1µF
2
C8
0.1µF
D3
3
LX
+3.3V AT 1.5A
VOUT
Evaluates: MAX1530/MAX1531
MAX1531 Evaluation Kit
MAX1531 Evaluation Kit
Evaluates: MAX1530/MAX1531
PIN
C25
4.7µF
VOUT
C26
1µF
L2
22µH
D2
6
56
12
VCC
3
SET
U2
EXT
5
N2
3
4
STEP_UP
MAX1522
1
JU16
2
4
SHDN
3
FB
GND
1
2
R31
110kΩ
1%
C24
10µF
R32
10.0kΩ
1%
R33
0.050Ω
Figure 2. MAX1531 EV Kit Schematic—Sheet 2 of 2
______________________________________________________________________________________
11
Evaluates: MAX1530/MAX1531
MAX1531 Evaluation Kit
Figure 3. MAX1531 EV Kit Component Placement Guide—
Component Side
Figure 4. MAX1531 EV Kit PC Board Layout—Component Side
Figure 5. MAX1531 EV Kit PC Board Layout—GND Layer 2
Figure 6. MAX1531 EV Kit PC Board Layout—VCC Layer 3
12
______________________________________________________________________________________
MAX1531 Evaluation Kit
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 ____________________ 13
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Evaluates: MAX1530/MAX1531
Figure 7. MAX1531 EV Kit PC Board Layout—Solder Side
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