19-0967; Rev 0; 9/07
MAX15008 Evaluation Kit
General Description
The MAX15008 evaluation kit (EV kit) is a complete,
fully assembled and tested printed-circuit board (PCB)
that demonstrates the capabilities of the MAX15008.
The MAX15008 features a configurable LDO voltage
regulator, a voltage tracker, and an overvoltage protec-
tor. The LDO is configured to 5V, 300mA output. The
voltage tracker is configured to track the LDO output
voltage and provides up to 50mA. The overvoltage pro-
tector threshold is configured to 17.7V.
The EV kit circuit features a
RESET
output signal to indi-
cate output fault and normal operating conditions. The
EV kit circuit board can also be used to evaluate the
MAX15009, MAX15010
†
, or MAX15011
†
ICs.
†
Future
Features
♦
Wide Operating Supply Voltage Range: 5V to 40V
♦
300mA LDO Configured to 5V (Supply Voltage ≥
6.5V)
♦
50mA Voltage Tracker
♦
Configurable Overvoltage Protector Threshold
♦
Output Signal (RESET) for Circuit Monitoring
♦
Can be Used to Evaluate the MAX15009,
MAX15010
†
, or MAX15011
†
ICs
♦
Fully Assembled and Tested
Evaluates: MAX15008–MAX15011
product—contact factory for availability.
Ordering Information
PART
MAX15008EVKIT+
TYPE
EV Kit
+Denotes
lead-free and RoHS-compliant.
Component List
DESIGNATION
C1
QTY
1
DESCRIPTION
10µF ±20%, 50V aluminum
electrolytic capacitor (C case)
Panasonic EEEFK1H100UR
0.1µF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H104K
0.15µF ±10%, 25V X7R ceramic
capacitor (0603)
TDK C1608X7R1E154K
3.3µF ±20%, 50V X7R ceramic
capacitor (1210)
TDK C3225X7R1H335M
22µF ±20%, 16V X5R ceramic
capacitor (1206)
Murata GRM31CR61C226M or
Taiyo Yuden EMK316BJ226M
10µF ±20%, 35V aluminum
electrolytic capacitor (B case)
Panasonic EEEFK1V100UR
22µF ±20%, 50V aluminum
electrolytic capacitor (D case)
Panasonic EEEFK1H220P
DESIGNATION
C8, C9, C10
C11, C13
C12
D1
JU1–JU4
N1
R1, R4, R6,
R12–R15
R2
R3, R5, R8,
R10, R11
R7, R9
U1
—
—
QTY
0
0
0
1
4
1
0
1
5
2
1
4
1
DESCRIPTION
Not installed, ceramic capacitors
(0603)
Not installed, aluminum electrolytic
capacitors (D case)
Not installed, ceramic capacitor
(1210)
54V, 5W TVS diode (SMB)
Diodes Inc. SMBJ54A
2-pin headers
100V, 44A n-channel MOSFET (D
pack)
Fairchild FDD3672
Not installed, resistors (0603)
0Ω ±5% resistor (0603)
10kΩ ±1% resistors (0603)
133kΩ ±1% resistors (0603)
MAX15008ATJ+ (32-pin TQFN-EP)
Shunts (JU1–JU4)
PCB: MAX15008 Evaluation Kit+
C2
1
C3
1
C4
1
C5
1
C6
1
C7
1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.
MAX15008 Evaluation Kit
Evaluates: MAX15008–MAX15011
Quick Start
Recommended Equipment
• Two 5V to 40V, 1A adjustable power supplies
• Four voltmeters
11) Verify that the OUT_PROTECT output measures 10V.
12) Verify that the
RESET
output signal measures 5V.
13) The EV kit is ready for further testing.
Detailed Description
The MAX15008 EV kit is a fully assembled and tested
circuit that demonstrates the capabilities of the
MAX15008. The MAX15008 features a configurable LDO
voltage regulator, a voltage tracker, and an overvoltage
protector. The LDO is configured to 5V and provides up
to 300mA. The voltage tracker is configured to track the
LDO output voltage and provides up to 50mA. The over-
voltage protector threshold is configured to 17.7V with
resistors R9 and R10. The LDO output voltage is config-
ured with external resistors R1 and R2. The tracker out-
put voltage can be configured to track a wide range of
voltages up to 35V by replacing resistors R3–R6. The EV
kit input-voltage range is up to 40V, but may have to be
decreased to not exceed the maximum continuous
power dissipation rating of the MAX15008 IC.
The EV kit
RESET
output signal can be used to monitor
the LDO output operating conditions or to reset circuitry
connected at the LDO output.
Procedure
The MAX15008 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below for simple
board operation.
Caution: Do not turn on the power
supply until all connections are completed.
1) Verify that shunts are installed across jumpers JU1
(LDO enabled), JU2 (HOLD enabled), JU3 (tracker
enabled), and JU4 (overvoltage protector enabled).
2) Set the first power supply to 10V and disable the
output. Connect the positive terminal of this power
supply to the IN PCB pad. Connect the ground ter-
minal of this power supply to the SGND PCB pad
located next to the IN pad.
3) Set the second power supply to 8V and disable the
output. Connect the positive terminal of this power
supply to the TRACK PCB pad. Connect the ground
terminal of this power supply to the SGND PCB pad
located next to the TRACK pad.
4) Connect a voltmeter across the OUT_LDO and
SGND PCB pads.
5) Connect a voltmeter across the OUT_TRK and
SGND PCB pads.
6) Connect a voltmeter across the OUT_PROTECT and
PGND PCB pads.
7) Connect a voltmeter across the
RESET
and SGND
PCB pads.
8) Turn on the IN and TRACK power supplies.
9) Verify that the OUT_LDO output measures 5V.
10) Verify that the OUT_TRK output measures 5V.
Input Power Supplies
The MAX15008 EV kit requires an input power source of
5V to 40V, 1A connected across IN and SGND and anoth-
er 5V to 40V, 1A power source connected across TRACK
and SGND for normal operation. The power source con-
nected to IN supplies power to the MAX15008 IC, the LDO
input, and the overvoltage protector input, while the power
source connected to TRACK supplies power to the tracker
input. The overvoltage protector input (IN2) can be sepa-
rated from the main input (IN) by cutting open the short-
ing trace between the IN and IN2 PCB pads. Connect a
separate power supply across the IN2 and PGND PCB
pads and install a 4.7µF to 10µF electrolytic capacitor at
C11. In order to evaluate the LDO performance at 5V out-
put, never set the IN supply voltage below 6.5V.
Component Suppliers
SUPPLIER
Diodes Inc.
Fairchild Semiconductors
Murata Mfg. Co., Ltd.
Panasonic Corp.
Taiyo Yuden
TDK Corp.
PHONE
805-446-4800
888-522-5372
770-436-1300
800-344-2112
800-348-2496
847-803-6100
www.diodes.com
www.fairchildsemi.com
www.murata.com
www.panasonic.com
www.t-yuden.com
www.component.tdk.com
WEBSITE
Note:
Indicate that you are using the MAX15008 when contacting these component suppliers.
2
_______________________________________________________________________________________
MAX15008 Evaluation Kit
LDO Regulator
The MAX15008 EV kit’s 300mA LDO output (OUT_LDO)
is configured to the 5V default output voltage by resis-
tor R2, which connects the FB_LDO pin to SGND. The
LDO input accepts a power source up to 40V.
However, operating the LDO at maximum conditions
can exceed the maximum continuous power dissipation
rating of the MAX15008 IC. This will cause the IC to
shut down after exceeding the internal thermal shut-
down threshold. The LDO output voltage can be recon-
figured between 1.8V and 11V by removing the 0Ω R2
resistor and installing resistors at R1 and R2. Use the
following equation to select new resistor values:
⎛
OUT _ LDO
⎞
following equation to2
× ⎜
new resistor
⎟
values:
R1
=
R select
−
1
⎝
1.235V
⎠
where R2 is less than 50kΩ and OUT_LDO is the
desired LDO output voltage.
LDO Control Logic
The MAX15008 LDO features two logic inputs (EN_LDO
and
HOLD)
to enable or disable the output during
power-on or normal operating conditions. The EV kit
features jumpers JU1 and JU2, which can be used to
set the EN_LDO and
HOLD
input pins, respectively.
See Table 1 for jumpers JU1 and JU2 configuration.
Evaluates: MAX15008–MAX15011
Table 1. LDO Control Logic (Jumpers JU1 and JU2)
OPERATION STATE
SHUNT STATUS
(JU1—EN_LDO)
Not installed
Installed
Hold Setup
Hold
Off
Installed
Not installed
Not installed
SHUNT STATUS
LDO OUTPUT
(JU2—HOLD)
X
X
Installed
Enabled
Installed
Not installed*
Disabled
LDO remains enabled if the shunt is removed from
jumper JU1
LDO is disabled if shunt on jumper JU2 is removed,
while shunt on jumper JU1 is not installed
Disabled
Enabled
OPERATING CONDITIONS
EN_LDO pin is connected to ground SGND through
an internal pulldown
EN_LDO pin is connected to IN
Shunt is installed on jumper JU2, while shunt on
jumper JU1 is in the installed state
Initial Power On
X = Don’t care.
*The
HOLD
pin is internally driven to OUT_LDO if the shunt on jumper JU2 is not installed.
_______________________________________________________________________________________
3
MAX15008 Evaluation Kit
Evaluates: MAX15008–MAX15011
Voltage Tracker
The MAX15008 voltage tracker input power supply, of
up to 40V, must be connected to the TRACK PCB pad.
The tracker output (OUT_TRK) can source up to 50mA
and is configured to track the OUT_LDO output voltage
by connecting the ADJ pin to OUT_LDO through resis-
tor R3, and connecting the FB_TRK pin to OUT_TRACK
through resistor R5. The ADJ pin voltage setting sets
the feedback tracker voltage threshold at the FB_TRK
pin. This feature offers the flexibility of setting the track-
er output at a lower, equal to, or higher than OUT_LDO
output voltage. Use the following equations to select
new resistor values for R3–R6 to reconfigure the
OUT_TRACK tracking voltage:
⎛
R4
⎞
V
ADJ
=
OUT _ LDO
⎜
⎟
⎝
R3
+
R4
⎠
V
FB _ TRK
=
TRK
=
V
ADJ
V
FB _
V
ADJ
⎛
OUT _ TRK
⎞
5
=
R6
× ⎜ ⎜
RR5
=
R6
× ⎛
OUT _ TRK
−⎟
1
⎞
−
1
⎟
⎝ ⎝
V
FB _ TRK
V
FB _ TRK
⎠ ⎠
where OUT_LDO is the LDO output voltage, V
ADJ
is the
voltage setting at the ADJ pin, V
FB_TRK
is the feedback
voltage, which equals the voltage set at the ADJ pin,
and OUT_TRK is the new tracking voltage. V
ADJ
must
be greater than 1.1V and less than TRACK - 0.5V. If
installed, resistors R4 and R6 must be less than or equal
to 50kΩ. V
ADJ
can be set to 1.235V by installing a 0Ω
(0603 size) surface-mount resistor at R13. If the tracker
output-voltage setting exceeds 35V, capacitor C6 must
be replaced with a higher voltage-rated capacitor.
where R10 is typically 10kΩ and OUT_PROTECT is the
desired overvoltage threshold.
The EV kit overvoltage protector can be reconfigured to
operate in overvoltage-limiter mode by cutting open the
shorting trace at resistor R15 and installing a 0Ω resistor
at R14. In this mode, when the circuit detects an overvolt-
age condition at the output load (OUT_PROTECT), the IC
turns off N1 until the load lowers the OUT_PROTECT
voltage below the overvoltage threshold. If the IN2 volt-
age is greater than the overvoltage threshold, the IC will
attempt to regulate the OUT_PROTECT voltage around
this threshold.
The overvoltage threshold for overvoltage-limiter mode
operation is configured to 17.7V by resistors R7 and
R8. Use the following equation to select new resistor
values to modify the overvoltage-limiter mode overvolt-
age threshold:
⎛
OUT _ PROTECT
⎞
R7
=
R8
× ⎜
−
1
⎟
⎝
⎠
1.235V
where R8 is typically 10kΩ and OUT_PROTECT is the
new overvoltage threshold. Exercise caution when
operating the overvoltage protector in overvoltage-
limiter mode. Refer to the
Overvoltage-Limiter Mode
section in the MAX15008/MAX15010 IC data sheet for
details.
Overvoltage Protector
The MAX15008 EV kit overvoltage protector is config-
ured to operate in overvoltage switch mode. When the
circuit detects an overvoltage condition at the IN2 input
(or IN if IN2 is not separated from IN), the IC turns off n-
channel MOSFET N1 to isolate the power source from
the load. When the voltage at the IN2 input decreases
below the overvoltage threshold, the MAX15008 turns
on N1, reconnecting the power source to the load. The
overvoltage threshold is configured to 17.7V by resis-
tors R9 and R10. Use the following equation to select
new resistor values to modify the overvoltage switch
mode overvoltage threshold:
⎛
OUT _ PROTECT
⎞
R9
=
R10
× ⎜
−
1
⎟
⎝
⎠
1.235V
Voltage Tracker Enable
The voltage tracker can be enabled or disabled by
configuring jumper JU3. See Table 2 for jumper JU3
configuration.
Table 2. Voltage Tracker (Jumper JU3)
SHUNT STATUS
Installed
Not installed
EN_TRK PIN
Connected to IN
Connected to ground
SGND with internal
pulldown
VOLTAGE
TRACKER
Enabled
Disabled
4
_______________________________________________________________________________________
MAX15008 Evaluation Kit
Note:
The overvoltage protector does not provide cur-
rent-limiting protection. Verify that the IN2 input supply
current is limited, according to the OUT_PROTECT
load, and that the current ripple rating of capacitors C7
and C11, which is recommended for separate power
operation, is not exceeded.
Evaluating the MAX15009, MAX15010, and
MAX15011
The MAX15008 EV kit PCB can be used to evaluate the
MAX15009, MAX15010, or MAX15011 ICs. Remove the
MAX15008 IC (U1) and replace it with any of the three
ICs. The MAX15010 IC integrates the same functions as
the MAX15008 minus the overvoltage protector. The
MAX15009 IC integrates an LDO, a switched output, and
an overvoltage protector. The MAX15011 IC integrates
the same functions as the MAX15009, minus the over-
voltage protector. When evaluating the MAX15009 or
MAX15011 ICs, components C8, C10, and R12 must be
installed. Refer to the MAX15008/MAX15010 or the
MAX15009/MAX15011 IC data sheets for a complete
description of part-to-part differences and configuration.
When evaluating the MAX15010 or MAX15011, it is rec-
ommended either to cut the trace connecting the IN
PCB pad to the IN2 PCB pad (drain of MOSFET N1), or
to connect the gate of N1 to ground by installing a low-
value (0603 size) resistor across the C9 PCB pads.
Also, remove resistor R9 to prevent current leakage
from the IN input.
Evaluates: MAX15008–MAX15011
Overvoltage Protector Enable
The overvoltage protector can be enabled or disabled
by configuring jumper JU4. See Table 3 for jumper JU4
configuration.
Table 3. Overvoltage Protector (Jumper
JU4)
SHUNT STATUS
Installed
Not installed
EN_PROT PIN
Connected to IN
Connected to
ground SGND with
internal pulldown
OVERVOLTAGE
PROTECTOR
Enabled
Disabled
RESET
Timeout Period
The MAX15008 EV kit features output signal
RESET
for
monitoring output OUT_LDO. The
RESET
output is
asserted high (OUT_LDO voltage) when output
OUT_LDO exceeds the voltage threshold of 92.5% of
the programmed output voltage for the configured time-
out period (t
TIMEOUT)
of 93ms. Replacing capacitor C3
with a different value reconfigures the timeout period.
Use the following equation to select a new capacitor
value for C3 when adjusting the timeout period:
t
×
2
μ
A
C3
=
TIMEOUT
1.235V
where t
TIMEOUT
is in seconds (s) and C3 is the new
capacitor value in farads.
_______________________________________________________________________________________
5