19-3520; Rev 0; 11/04
MAX1531 Evaluation Kit
General Description
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-refer-
ence 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 reg-
ulator for the TFT gate-off supply. The source-driver
supply, the gamma-reference supply, the gate-on sup-
ply, 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 switch-
ing regulator, and overload protection for the source-
drive linear regulator. Operation at 500kHz allows the
use of small surface-mount components. The EV kit
also evaluates the MAX1530.
Features
♦
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)
♦
+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
♦
Also Evaluates the MAX1530 (IC Replacement
Required)
♦
Low-Profile, Surface-Mount Components
♦
Fully Assembled and Tested
Evaluates: MAX1530/MAX1531
Component List
DESIGNATION
C1, C4
C2, C23
C3
QTY
2
0
1
DESCRIPTION
1µF
±10%,
25V X7R ceramic
capacitors (0805)
TDK C2012X7R1E105K
Not installed capacitors (0603)
4.7µF
±10%,
25V X7R ceramic
capacitor (1210)
TDK C3225X7R1E475K
0.1µF
±10%,
50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H104K
22µF
±20%,
6.3V X7R ceramic
capacitor (1206)
TDK C3216X7R0J226M
Ordering Information
PART
MAX1531EVKIT
TEMP RANGE
0°C to +70°C
IC PACKAGE
32 TQFN (5mm x 5mm)
C5, C6, C8,
C11, C14, C15,
C17, C18, C20
9
C7
1
________________________________________________________________
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.
MAX1531 Evaluation Kit
Evaluates: MAX1530/MAX1531
Component List (continued)
DESIGNATION
C9
QTY
1
DESCRIPTION
10µF
±20%,
6.3V X5R ceramic
capacitor (1206)
TDK C3216X5R0J106M
470pF
±10%,
50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H471K
0.47µF
±10%,
16V X7R ceramic
capacitors (0805)
TDK C2012X7R1C474K
4.7µF
±10%,
16V X7R ceramic
capacitors (1206)
TDK C3216X7R1C475K
0.47µF
±20%,
50V X7R ceramic
capacitor (1210)
TDK C3225X7R1H474M
2.2µF
±10%,
25V X7R ceramic
capacitors (1206)
TDK C3216X7R1E225K
10µF
±20%,
25V X5R ceramic
capacitor (1210)
TDK C3225X5R1E106M
1µF
±10%,
10V X5R ceramic
capacitor (0603)
TDK C1608X5R1A105K
100mA, 30V Schottky diodes (SOD-
523)
Central Semiconductor CMOSH-3
1A, 30V Schottky diode (S-flat)
Toshiba CRS02
250mA, 100V dual diodes (SOT23)
Central Semiconductor CMPD6001S
250mA, 75V high-speed silicon diode
(SOD-523)
Central Semiconductor CMOD4448
3-pin headers
2-pin headers
3-way jumpers (4 pins)
4-way jumpers (5 pins)
Q1, Q4
2
DESIGNATION
L1
L2
QTY
1
1
DESCRIPTION
10µH, 2.3A
DC
inductor
Sumida CDR7D28MN-100
22µH, 0.90A
DC
inductor
Sumida CDRH5D28-220
2.5A, 30V dual n-channel MOSFET
(Super SOT-6)
Fairchild Semiconductor FDC6561AN
5.2A, 30V n-channel MOSFET (Super
SOT-6)
Fairchild Semiconductor FDC633N
3A, 60V low-saturation pnp bipolar
transistors
(SOT-223)
Fairchild Semiconductor NZT660A
200mA, 40V pnp bipolar transistors
(SOT23)
Central Semiconductor CMPT3906
200mA, 40V npn bipolar transistors
(SOT23)
Central Semiconductor CMPT3904
17.8kΩ
±1%
resistor (0805)
10.7kΩ
±1%
resistors (0805)
124kΩ
±1%
resistor (0805)
20.0kΩ
±1%
resistor (0805)
100kΩ
±5%
resistors (0805)
6.8kΩ
±5%
resistors (0805)
10.0kΩ
±1%
resistors (0805)
301kΩ
±1%
resistor (0805)
221kΩ
±1%
resistor (0805)
121kΩ
±1%
resistor (0805)
68.1kΩ
±1%
resistors (0805)
43.2kΩ
±1%
resistor (0805)
1.5kΩ
±5%
resistor (0805)
75.0kΩ
±1%
resistor (0805)
200kΩ
±1%
resistor (0805)
10.5kΩ
±1%
resistor (0805)
C10
1
N1
1
C12, C19
2
N2
1
C13, C25
2
C16
1
Q2, Q3
2
C21, C22
2
Q5, Q6
R1
R2, R23
R3
R4
R5, R6, R7,
R11
R8, R17, R24,
R27
R9, R10, R19,
R32
R12
R13
R14
R15, R18
R16
R21
R22
R25
R26
2
1
2
1
1
4
4
4
1
1
1
2
1
1
1
1
1
C24
1
C26
1
D1, D6
2
D2
D3, D4, D5
1
3
D7
JU1,
JU12–JU16
JU2, JU3
JU4–JU7
JU8–JU11
1
6
2
4
4
2
_______________________________________________________________________________________
MAX1531 Evaluation Kit
Component List (continued)
DESIGNATION
R28
R29
R30
R31
R33
R34
R35, R36
R37, R38
R39–R42
U1
U2
None
None
QTY
1
1
1
1
1
0
2
2
4
1
1
16
1
DESCRIPTION
90.9kΩ
±1%
resistor (0805)
48.7kΩ
±1%
resistor (0805)
1Ω
±5%
resistor (0805)
110kΩ
±1%
resistor (0805)
0.050Ω
±1%
resistor (1206)
IRC LRC-LR 1206-01-R050-F
Not installed resistor (0805)
1.00Ω
±1%
resistors (0805)
10Ω
±5%
resistors (0805)
2.0kΩ
±5%
resistors (0805)
MAX1531ETJ (32-pin TQFN)
MAX1522EUT-T (6-pin SOT23)
Shunts (see table for jumper settings)
MAX1531 PC board
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 termi-
nal of the input power supply to the PGND pad.
8) Turn on the power supply and verify that the step-
down 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.
Evaluates: MAX1530/MAX1531
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 limi-
tations, 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.
Detailed Description
The MAX1531 EV kit contains a step-down switching
regulator, a linear regulator for a low-voltage logic sup-
ply, a high-current linear regulator for a source-driver
supply, a linear regulator for a gamma reference, a two-
stage positive charge pump with a positive high-volt-
age linear regulator, and a one-stage negative charge
pump with a negative linear regulator. The EV kit oper-
ates from a +10.5V and +24V DC power supply, which
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.
Component Suppliers
SUPPLIER
Central Semiconductor
Fairchild
IRC
Sumida
TDK
Toshiba
PHONE
631-435-1110
888-522-5372
361-992-7900
847-545-6700
847-803-6100
949-455-2000
FAX
631-435-1824
—
361-992-3377
847-545-6720
847-390-4405
949-859-3963
WEBSITE
www.centralsemi.com
www.fairchildsemi.com
www.irctt.com
www.sumida.com
www.component.tdk.com
www.toshiba.com/taec
Note:
Indicate you are using the MAX1530/MAX1531 when contacting these manufacturers.
_______________________________________________________________________________________
3
MAX1531 Evaluation Kit
Evaluates: MAX1530/MAX1531
can provide at least 2A. The step-down switching regu-
lator’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 regula-
tor 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 step-
down switching-regulator output voltage can be adjust-
ed 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 out-
put 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 regu-
lator’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 lin-
ear 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 posi-
tive 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 reg-
ulator’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 pro-
vide greater than 50mA. The negative linear regulator’s
output can be adjusted between 0V and its input volt-
4
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) soft-
starts. The gamma reference, the gate-on supply, the
source-driver supply, and the gate-off supply can soft-
start in any sequence by setting the appropriate
jumpers (see the
Power-Up Sequencing
section).
The EV kit includes a current-limit circuit for the step-
down switching regulator. The current-limit threshold is
set by resistor-dividers R12, R13, and the R
DS(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 over-
load protection for the source-driver supply voltage. The
MAX1531 will shut down if the source-driver supply
exceeds a current threshold. The output current over-
load 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
None
1-2
(Default)
2-3
EN PIN
Connected to GND
Connected to PIN
through resistor-
dividers R3 and R4
Connected to VL
MAX1531 (U1)
IC STATUS
Disabled
Enabled
when V
PIN
> 9V
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
Evaluates: MAX1530/MAX1531
Table 2. Jumper JU2 Functions
SHUNT
LOCATION
Installed
None
(Default)
FREQ PIN
Connected to GND
Connected to VL
through R5
MAX1531 EV KIT
FREQUENCY
Frequency = 250kHz
Frequency = 500kHz
Installed
Connected to
GND
Table 3. Jumper JU3 Function
SHUNT
LOCATION
SEQ PIN
MAX1531 STATE
Sequence block disabled.
VSRC, VGAM, GON, and
GOFF disabled, regardless of
ONL2 to ONL5 voltage levels.
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 regu-
lators 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
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
exceeds 1.24V. JU4 to JU7 enable immediate startup
of their respective regulator after the step-down regula-
tor reaches regulation and SEQ is high, without addi-
tional 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
1-2
JU8 SHUNT
LOCATION
Don’t Care
ONL2 PIN
Connected to VL
through R39
Connected to
GND
Connected to R14
Connected to R15
Connected to R16
Connected to C11
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.
Gamma linear regulator soft-starts about 6ms after sequence
block enabled.
Gamma linear regulator soft-starts about 9ms after sequence
block enabled.
Gamma linear regulator soft-starts about 12ms after sequence
block enabled.
Gamma linear regulator soft-starts about 15ms after sequence
block enabled.
1-4
Don’t Care
1-2
1-3
(Default)
1-3
(Default)
1-4
1-5
_______________________________________________________________________________________
5
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