MAX16050 EV Kit

19-4199; Rev 0; 7/08
MAX16050 Evaluation Kit
The MAX16050 evaluation kit (EV kit) is a complete, fully
assembled and tested multivoltage sequencer circuit that
demonstrates the capability of the 4-channel MAX16050
and 5-channel MAX16051 sequencing ICs. The
MAX16050 EV kit monitors up to nine DC-DC converter
outputs and ensures proper power-up and power-down
conditions for systems requiring voltage sequencing.
The EV kit features RESET output signals to indicate an
undervoltage condition, or when SHDN or FAULT signals are pulled low. Additionally, dedicated OV_OUT
outputs indicate an overvoltage fault when any of the
EV kit’s inputs go above the overvoltage threshold. The
EV kit is capable of evaluating the MAX16050 and
MAX16051 individually. The EV kit can be configured
for daisy chaining these two devices together, which
enables the user to sequence and monitor up to nine
voltages across both devices. The MAX16050 EV kit
also provides PCB pads for low-current MOSFETs that
are controlled using the MAX16050 and MAX16051
charge-pump outputs.
The MAX16050 EV kit utilizes two power supplies, one
for each IC. Each power supply can range from 2.7V to
13.2V, allowing the user to operate directly from an
intermediate bus voltage. The MAX16050 EV kit also
requires an additional 2.2V to 5.5V power supply for the
pullup resistors’ open-drain logic outputs.
Features
♦ Quick Demo Mode Evaluation Without DC-DC
Converters
♦ Monitors and Sequences Up to Nine DC-DC
Converter Outputs
♦ Reverse-Sequencing Operation
♦ Configurable Sequencing Order (MAX16050 Only)
♦ Daisy-Chaining Operation of the MAX16050 and
MAX16051
♦ Overvoltage and Power-Good Monitoring
♦ Fully Assembled and Tested
Ordering Information
PART
TYPE
MAX16050EVKIT+
EV Kit
+Denotes lead-free and RoHS compliant.
Component List
DESIGNATION
QTY
Not installed, ceramic capacitors
(1206)
C11, C21
2
0
Not installed, ceramic capacitors
(0805)
2200pF ±5%, 50V C0G ceramic
capacitors (0805)
Murata GRM2165C1H222J
GND (3)
3
PC large black test points
2
0.1μF ±10%, 25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E104K
DESIGNATION
QTY
C1, C2, C12
0
C3, C13
C4, C15
C5, C14
C6–C9, C16-C19,
C22
C10, C20
DESCRIPTION
2
1μF ±10%, 25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
9
0.01μF ±10%, 25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E103K
2
DESCRIPTION
GND (2)
2
PC mini black test points
J1
1
2 x 16 header
J2
1
2 x 20 header
J3–J6
4
2-pin headers
JU1–JU7, JU10,
JU11, JU12, JU15
11
3-pin headers
JU8, JU9, JU13,
JU14
4
2-pin headers
N1, N2
0
Not installed, n-channel
MOSFETs (3 SOT23)
1200pF ±5%, 50V C0G ceramic
capacitors (0805)
Murata GRM2195C1H122J
________________________________________________________________ Maxim Integrated Products
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.
1
Evaluates: MAX16050/MAX16051
General Description
Evaluates: MAX16050/MAX16051
MAX16050 Evaluation Kit
Component List (continued)
DESIGNATION
QTY
DESCRIPTION
DESIGNATION
QTY
R35
1
20.5kΩ ±1% resistor (0805)
SW1
1
4-position DIP switch
SW2
1
10-position DIP switch
U1_VCC, U2_VCC,
VPULLUP
3
PC large red test points
U1
1
4-channel voltage sequencer
(28 TQFN-EP*)
Maxim MAX16050ETI+
U2
1
5-channel voltage sequencer
(28 TQFN-EP*)
Maxim MAX16051ETI+
—
32
Shunts (J1, J2, JU1–JU15)
—
1
PCB: MAX16050 Evaluation Kit+
OUTPUT1,
OUTPUT2,
U1_CP_OUT,
U1_EN,
U1_OV_OUT,
U1_REM,
U1_RESET,
U2_CP_OUT,
U2_EN,
U2_OV_OUT,
U2_REM,
U2_RESET
12
R1, R12, R20, R32
4
86.6kΩ ±1% resistors (0805)
R2, R4, R10, R13,
R22, R24, R30,
R33, R36
9
16.5kΩ ±1% resistors (0805)
R3, R23
2
30.1kΩ ±1% resistors (0805)
R5, R11, R14, R25,
R31, R34, R37
7
10kΩ ±1% resistors (0805)
R6, R26
2
634kΩ ±1% resistors (0805)
SUPPLIER
R7, R27
2
261kΩ ±1% resistors (0805)
R8, R28
2
698kΩ ±1% resistors (0805)
R9, R29
2
61.9kΩ ±1% resistors (0805)
Murata
Electronics
North
America, Inc.
R15, R21
0
Not installed, resistors—short
(0805)
R16–R19,
R38–R41
8
10kΩ ±5% resistor (0805)
PC mini red test points
*EP = Exposed pad.
Quick Start
Required Equipment
Before beginning, the following equipment is needed:
• MAX16050 EV kit
•
•
DC power supplies: 3.5V/100mA, 5V/50mA
2-channel oscilloscope
Procedure
The MAX16050 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below to verify
board operation. Caution: Do not turn on the power
supplies until all connections are completed.
1) Verify that headers J1 and J2 and jumpers
JU1–JU14 are configured for demo mode configuration (see Table 1).
2) Verify that switches SW1 and SW2 are set to the off
position.
2
DESCRIPTION
Component Suppliers
PHONE
WEBSITE
770-436-1300 www.murata-northamerica.com
Note: Indicate that you are using the MAX16050 or MAX16051
when contacting these component suppliers.
3) Connect the positive terminal of the 3.5V power
supply to the U1_VCC and U2_VCC test points.
Connect the ground terminal of this power supply to
the respective GND test points.
4) Connect the positive terminal of a 5V power supply
to the VPULLUP test point. Connect the ground terminal of this power supply to the GND test point.
5) Connect oscilloscope channels 1 and 2 to the
U1_RESET and U2_RESET test points, respectively.
Connect the ground leads to the nearby black GND
test points.
6) Turn on the VCC power supply and adjust the voltage to 3.5V.
7) Turn on the VPULLUP power supply and adjust the
voltage to 5V.
8) Verify that both U1_RESET and U2_RESET signals
are high.
9) The EV kit is ready for further testing.
_______________________________________________________________________________________
MAX16050 Evaluation Kit
JUMPER
MAX16050
MAX16051
J1
J2
SIGNAL
EV kit operation
JU1
JU10
OUT_
JU2
JU11
EN
SHUNT
POSITION
1-2*, 2-3
2-3 only
FUNCTION
Demo mode (see Figure 1)
DC-DC mode (see Figure 1)
1-2
OUT_ connects to VCC through resistor
2-3*
OUT_ connects to VPULLUP through resistor
1-2*
Controllers enabled at U1_VCC/U2_VCC > 3.2V
2-3
Controllers disabled
1-2
Connects to CP_OUT through resistor
2-3*
Connection dependent on jumpers JU1 and JU10
configuration
JU3
JU12
OUT3
JU4
—
SEQ1
Not installed*
JU5
—
SEQ2
Not installed*
JU6
—
SEQ3
Not installed*
JU7
JU15
EN_HOLD
1-2*
Normal operation of EN and SHDN functions
2-3
Ignores high-to-low transitions at SHDN and EN
Not installed*
JU8
JU13
SHDN
JU9
JU14
FAULT
Installed
Not installed*
Installed
Sequence order: OUT1, OUT2, OUT3, OUT4
Controller enabled or externally driven
Controllers disabled. Reverse power-down sequencing.
RESET asserts low.
Normal operation
Disables controller. Initiates simultaneous power-down of
OUT. RESET asserts low.
*Default position (demo mode operation).
Detailed Description of Hardware
The MAX16050 evaluation kit (EV kit) evaluates the 4channel MAX16050 and 5-channel MAX16051 powersupply sequencing ICs. The MAX16050 EV kit monitors
up to nine DC-DC converter outputs, thus ensuring
proper power-up and power-down conditions for systems requiring voltage sequencing. During powerdown, the outputs can be reverse-sequenced by
driving SHDN low. The MAX16050 EV kit’s VCC powersupply inputs require 2.7V to 13.2V and VPULLUP
requires 2.2V to 5.5V.
The MAX16050 EV kit can operate in DC-DC mode or in
demo mode. DC-DC mode uses the MAX16050 and
MAX16051 to control external DC-DC converters, and
without demo mode facilitates stand-alone evaluation
without external DC-DC converters.
The EV kit features RESET output signals to indicate an
undervoltage condition, or when shunts are installed
across the jumpers labeled SHDN or FAULT.
Additionally, dedicated OV_OUT outputs indicate overvoltage faults when any of the monitored EV kit IN inputs
go above their overvoltage thresholds. The EV kit also
provides test points OUTPUT1 and OUTPUT2 for low-current n-channel MOSFETs N1 and N2, respectively, which
are controlled by the MAX16050 and MAX16051 chargepump outputs. Refer to the MAX16050/MAX16051 IC
data sheet for additional information on selecting appropriate MOSFETs when driving external MOSFETs using
the charge-pump outputs.
Power-Supply Connections
(U1_VCC, U2_VCC, VPULLUP)
The MAX16050 EV kit requires input voltages of 2.7V to
13.2V connected at the U1_VCC and U2_VCC test
points to power the MAX16050 and MAX16051 controllers, respectively. The power supplies must provide
at least 50mA of current. VPULLUP requires an input
voltage of 2.2V to 5.5V connected to the VPULLUP test
point and supplies power to the EV kit’s pullup resistor
open-drain outputs. The VPULLUP power supply must
provide at least 50mA of current. Additional surfacemount 1206 PCB pads are provided for adding additional bulk capacitance at C1, C2, and C12 for the EV kit
power-supply inputs. Header pins J3–J6 are available to
use as ground reference for signal and voltage probing.
_______________________________________________________________________________________
3
Evaluates: MAX16050/MAX16051
Table 1. MAX16050/MAX16051 EV Kit Jumper Description
Evaluates: MAX16050/MAX16051
MAX16050 Evaluation Kit
DC-DC Mode
For DC-DC mode operation, connect the DC-DC converter outputs and EN/SHDN inputs to the EV kit’s IN_
and OUT_ header pins, respectively, and place shunts
across pins 2-3 of headers J1 and J2. Header J1 drives
the U1_IN1–U1_IN4 MAX16050 inputs and header J2
drives the U2_IN1–U2_IN5 MAX16051 inputs. See
Table 1 and Figure 1 for headers J1 and J2 configuration for DC-DC and demo modes of operation. By
default, the input-voltage thresholds are set according
to Table 2.
The sequence delay between each of the OUT_ outputs
is the time required for the external converter voltage to
exceed the undervoltage threshold, the respective
channel open-drain output OUT_ going high impedance, and the additional time delay set by external delay
capacitors C10 and C20. As each IN_ voltage meets its
respective threshold, the next OUT_ in the sequence
goes high impedance (open-drain output), enabling the
next power supply, which is then monitored by the next
input stage. When all the voltages exceed their respective thresholds, RESET goes high after the reset timeout
period set by capacitors C11 and C21.
Table 2. Input Channel Threshold Voltages
INPUT CHANNEL
INPUT
THRESHOLD
VOLTAGE (V)
RESISTORS
U1_IN1, U2_IN1
3.13
R12/R13, R32/R33
U1_IN2, U2_IN2
2.28
R9/R10, R29/R30
U1_IN3, U2_IN3
1.71
R6/R7, R26/R27
U1_IN4, U2_IN4
1.43
R3/R4, R23/R24
U2_IN5
1.14
R35/R36
Demo Mode
The MAX16050 EV kit allows quick evaluation of the
MAX16050 and MAX16051 ICs individually without interfacing DC-DC converters to the kit’s IN and OUT header
pins. Place shunts across pins 1-2 and pins 2-3 of headers J1 and J2 to operate the MAX16050 EV kit in demo
mode. In demo mode, VCC or VPULLUP powers the
inputs to the respective IN_ channels with the OUT_
pullup voltage. Demo mode operation requires a minimum 3.5V applied at the VCC or VPULLUP PCB input
pads. See Table 1 and Figure 1 for proper shunt placement when operating the MAX16050 EV kit in demo
mode. Note that when operating the MAX16050 EV kit in
demo mode, both OV_OUT signals will be asserted low.
To daisy chain the MAX16050 and MAX16051 while
operating the EV kit in demo mode, See the Configuring
the MAX16050 EV Kit for Daisy-Chain Operation (SW1)
section.
Input Channel Threshold Voltages (IN_)
The EV kit input-voltage thresholds are set to operate
with 3.3V, 2.5V, 1.8V, 1.5V, and 1.2V (MAX16051) voltage systems. All input-voltage thresholds can be reconfigured by replacing the corresponding resistors, as
shown in Table 2. Refer to the Resistor Value Selection
section in the MAX16050/MAX16051 IC data sheet to
calculate the new resistor values when reconfiguring
the EV kit input thresholds.
OUT_ Pullup Voltage Selection (JU1, JU10)
Jumpers JU1 and JU10 select the OUT_ open-drain
pullup voltage. Place a shunt across pins 1-2 of
jumpers JU1 and JU10 to select the respective powersupply inputs (U1_VCC, U2_VCC) as the OUT_ logichigh voltage. Place shunts across pins 2-3 of jumpers
JU1 and JU10 to select VPULLUP as the OUT_ logichigh voltage. See Table 3 for proper jumper settings for
OUT_’s logic-high voltage configuration.
Figure 1. Headers J1/J2 Shunt Configurations for DC-DC and
Demo Mode Operation
4
_______________________________________________________________________________________
MAX16050 Evaluation Kit
Charge-Pump Outputs (CP_OUT)
The EV kit features test points (U1_CP_OUT,
U2_CP_OUT) to monitor the MAX16050 and MAX16051
charge-pump outputs. PCB pads are also available for
the installation of low-current SOT23 footprint n-channel
MOSFETs at N1 and N2.
The EV kit’s charge-pump outputs can also be used as
the pullup voltages for open-drain output OUT3 using
jumpers JU3 and JU12. See Table 5 for configuring
OUT3 to the respective charge-pump outputs.
Table 3. Jumpers JU1, JU10 Configuration
SHUNT
POSITION
OUT_ PULLUP RESISTOR VOLTAGE
SOURCE
1-2
OUT_ connects to VCC through resistor
2-3
OUT_ connects to VPULLUP through resistor
EN Control (JU2, JU11)
Jumpers JU2 and JU11 enable or disable the MAX16050
and MAX16051, respectively, for power-up sequencing
and simultaneous power-down operation. Install shunts
across pins 1-2 of jumpers JU2 and JU11 to initiate a
power-up sequence. Install a shunt across pins 2-3 to
power down the channels and to assert RESET. See
Table 4 for jumpers JU2 and JU11 configuration.
Table 5. Jumpers JU3, JU12 Configuration
SHUNT
POSITION
OUT3 PULLUP VOLTAGE
1-2
Connects to CP_OUT through resistor
2-3
Connection dependent on jumpers JU1/JU10
configuration (see Table 3)
Table 4. Jumpers JU2, JU11 Configuration
SHUNT
POSITION
MAX16050 Sequence Order
(JU4, JU5, JU6)
EN INPUT SETTING
1-2
EN connected to resistor-divider (controllers
enabled)
2-3
EN = GND (controllers disabled)
Jumpers JU4, JU5, and JU6 configure the MAX16050
sequencing order. The jumper settings allow up to 24
different power-up combinations. The MAX16051 does
not feature programmable power-supply sequencing
and powers up in a fixed order from U2_OUT1–U2_
OUT5. See Table 6 to configure the sequencing order
for U1_OUT1–U1_OUT4.
The voltage threshold of each analog EN input is configured to 3.17V using resistors R1/R2 (U1) and R20/R22
(U2). Use the following equation to calculate a new R1 or
R20 resistor value to change the enable threshold:
⎛ V
⎞
R A = 16. 5 x ⎜ EN − 1⎟
⎝ 0 . 5V ⎠
Table 6. MAX16050 Sequencing Control (JU4, JU5, JU6)
SHUNT POSITION
SEQUENCE ORDER
JU4
JU5
JU6
1ST
2ND
3RD
4TH
Not installed
Not installed
Not installed
U1_OUT1
U1_OUT2
U1_OUT3
U1_OUT4
Not installed
Not installed
2-3
U1_OUT1
U1_OUT2
U1_OUT4
U1_OUT3
Not installed
Not installed
1-2
U1_OUT1
U1_OUT3
U1_OUT2
U1_OUT4
Not installed
2-3
Not installed
U1_OUT1
U1_OUT3
U1_OUT4
U1_OUT2
Not installed
2-3
2-3
U1_OUT1
U1_OUT4
U1_OUT2
U1_OUT3
Not installed
2-3
1-2
U1_OUT1
U1_OUT4
U1_OUT3
U1_OUT2
Not installed
1-2
Not installed
U1_OUT2
U1_OUT1
U1_OUT3
U1_OUT4
Not installed
1-2
2-3
U1_OUT2
U1_OUT1
U1_OUT4
U1_OUT3
Not installed
1-2
1-2
U1_OUT2
U1_OUT3
U1_OUT1
U1_OUT4
_______________________________________________________________________________________
5
Evaluates: MAX16050/MAX16051
where VEN is the desired VCC undervoltage threshold,
0.5V is the MAX16050/MAX16051 EN threshold voltage,
and RA is the new resistor value for R1 or R20 in kilohms.
Caution: When operating the MAX16050 EV kit
U1_VCC or U2_VCC inputs with power supplies greater
than 5.5V, verify that shunts are installed across pins 2-3
of jumpers JU1 and JU10 to prevent operating the opendrain logic outputs above the maximum voltage rating.
Evaluates: MAX16050/MAX16051
MAX16050 Evaluation Kit
Table 6. MAX16050 Sequencing Control (JU4, JU5, JU6) (continued)
SHUNT POSITION
SEQUENCE ORDER
JU4
JU5
JU6
1ST
2ND
2-3
Not installed
Not installed
U1_OUT2
U1_OUT3
U1_OUT4
U1_OUT1
2-3
Not installed
2-3
U1_OUT2
U1_OUT4
U1_OUT1
U1_OUT3
2-3
Not installed
1-2
U1_OUT2
U1_OUT4
U1_OUT3
U1_OUT1
2-3
2-3
Not installed
U1_OUT3
U1_OUT1
U1_OUT2
U1_OUT4
2-3
2-3
2-3
U1_OUT3
U1_OUT1
U1_OUT4
U1_OUT2
2-3
2-3
1-2
U1_OUT3
U1_OUT2
U1_OUT1
U1_OUT4
2-3
1-2
Not installed
U1_OUT3
U1_OUT2
U1_OUT4
U1_OUT1
2-3
1-2
2-3
U1_OUT3
U1_OUT4
U1_OUT1
U1_OUT2
4TH
U1_OUT1
2-3
1-2
1-2
U1_OUT3
U1_OUT4
U1_OUT2
1-2
Not installed
Not installed
U1_OUT4
U1_OUT1
U1_OUT2
U1_OUT3
1-2
Not installed
2-3
U1_OUT4
U1_OUT1
U1_OUT3
U1_OUT2
1-2
Not installed
1-2
U1_OUT4
U1_OUT2
U1_OUT1
U1_OUT3
1-2
2-3
Not installed
U1_OUT4
U1_OUT2
U1_OUT3
U1_OUT1
1-2
2-3
2-3
U1_OUT4
U1_OUT3
U1_OUT1
U1_OUT2
1-2
2-3
1-2
U1_OUT4
U1_OUT3
U1_OUT2
U1_OUT1
EN_HOLD (JU7, JU15)
Jumpers JU7 and JU15 configuration setting allows the
MAX16050 and MAX16051 to ignore high-to-low transitions at the EN and SHDN inputs. Place a shunt across
pins 1-2 for normal operation of the EN and SHDN feature. Place a shunt across pins 2-3 to ignore high-to-low
transitions at EN and SHDN. See Table 7 for jumpers
JU7 and JU15 configuration.
SHDN Control (JU8, JU13)
Jumpers JU8 and JU13 initiate the MAX16050 and
MAX16051 for a reverse-sequencing event. Install
shunts on jumpers JU8 and JU13 to initiate a reversesequencing event. Remove the shunts at jumpers JU8
and JU13 for proper power-up operation when EN =
high. To drive SHDN externally, place a square-wave
signal with a 2V to 5.5V logic-high level at pin 1 of
jumpers JU8 or JU13. See Table 8 for jumpers JU8 and
JU13 configuration.
level at pin 1 of jumpers JU8 or JU14. Connect the signal ground to a convenient ground reference. See
Table 9 for jumpers JU9 and JU14 configuration.
Table 7. Jumpers JU7, JU15 Configuration
SHUNT
POSITION
EN_HOLD INPUT SETTING
1-2
Normal operation of EN and SHDN functions
2-3
Ignores high-to-low transitions at EN and SHDN
Table 8. Jumpers JU8, JU13 Configuration
SHUNT
POSITION
SHDN INPUT SETTING
Not
installed
Controller enabled or externally driven
Installed
Reverse power-down sequencing. RESET
asserts low.
FAULT Control (JU9, JU14)
Jumpers JU9 and JU14 control the MAX16050 and
MAX16051 input/output FAULT signal, respectively.
FAULT asserts low when any of the monitored IN voltages fall below its SET voltage threshold. As an output,
FAULT can be driven externally to initiate a simultaneous power-down of the DC-DC controllers. Install a
shunt across jumpers JU9 and JU14 to initiate a shutdown of the controllers. To drive FAULT externally,
place a square-wave signal with a 2V to 5.5V logic-high
6
3RD
Table 9. Jumpers JU9, JU14 Configuration
SHUNT
POSITION
FAULT INPUT SETTING
Not
installed
Normal operation
Installed
Disables controller. Initiates simultaneous power
down of OUT_. RESET asserts low.
_______________________________________________________________________________________
MAX16050 Evaluation Kit
C=
t DELAY − 34μs
5 × 10 5 Ω
where C is the capacitance of C10 or C20 in farads,
and tDELAY is in seconds.
Reset Timeout Control
The EV kit RESET signals assert low under the following
conditions:
1) Any monitored voltage falls below its input threshold.
2) EN falls below the enable threshold.
3) FAULT output is pulled low.
4) SHDN is pulled low (note that when SHDN is pulled
low, the controller initiates a reverse-sequence
power-down).
Table 10. SW2 Channel Bypass
SWITCH
BYPASS CHANNEL
1
U1_IN4
2
U1_IN3
3
U1_IN2
4
U1_IN1
5
U2_IN5
6
U2_IN4
7
U2_IN3
where C is the capacitance of C11 or C21 in farads,
and tTIMEOUT is in seconds.
8
U2_IN2
9
U2_IN1
Channel Bypassing (SW2)
10
Not used
Capacitors C11 and C21 set the tTIMEOUT period for U1
and U2 to 1.1ms, respectively. Replace the capacitors
with a different value to adjust the tTIMEOUT periods, or
remove the capacitors to set the tTIMEOUT period to
34μs. Use the following equation to calculate new
capacitor values when adjusting the tTIMEOUT period:
C=
t TIMEOUT − 34μs
5 x 10 5 Ω
DIP switch SW2 allows the MAX16050 EV kit to bypass
any unused channels and to power up successfully when
using fewer than four or five DC-DC converters with the
U1_IN1–U1_IN4 and U2_IN1–U2_IN5 inputs, respectively.
To bypass a channel, remove the shunts connected
across pins 1-2 and 2-3 of headers J1 or J2, and set the
respective SW2 switch to the on position. See Table 10
for the input channel assignment on switch SW2.
Logic Outputs (OV_OUT, RESET)
The MAX16050 EV kit features test points U1_OV_OUT,
U2_OV_OUT, U1_RESET, and U2_RESET to monitor
fault conditions on each controller. U1_OV_OUT and
U2_OV_OUT assert low when any of the monitored IN
voltages rise above their overvoltage threshold. See
Table 11 for the input channel overvoltage thresholds.
Table 11. Input Overvoltage Thresholds
INPUT CHANNEL
INPUT OVERVOLTAGE
THRESHOLD (V)
_IN1
3.43
_IN2
2.61
_IN3
1.89
_IN4
1.55
IN5 (MAX16051 only)
1.23
_______________________________________________________________________________________
7
Evaluates: MAX16050/MAX16051
Sequence Delay Control
Capacitors C10 or C20 set the tDELAY periods for U1
and U2 to 644μs, respectively. Replace the capacitors
with different values to adjust the tDELAY periods, or
remove the capacitors to set the t DELAY periods to
34μs. Use the following equation to calculate a new
capacitor value when adjusting the tDELAY period:
Evaluates: MAX16050/MAX16051
MAX16050 Evaluation Kit
Configuring the MAX16050 EV Kit for
Daisy-Chain Operation (SW1)
The MAX16050 EV kit can be configured for daisychain operation of the MAX16050 (U1) and the
MAX16051 (U2) by configuring DIP switch SW1 and
various jumpers. See Tables 12 and 13 for switch SW1
and the proper jumper configurations, respectively, to
configure the EV kit for daisy-chain operation. For proper daisy-chain operation of U1 and U2, all of SW1
switches should be set to the on position.
To initiate a power-up sequence, install a shunt across
pins 1-2 of jumper JU2 (U1_EN). U1_IN1–U1_IN4
sequence according to the shunt configurations of
jumpers JU4, JU5, and JU6 (Table 6). Upon U1_ inputs
rising above their respective thresholds, the U1_RESET
signal goes high and drives U2_EN input high (SW1-4)
allowing sequencing to commence on the MAX16051.
Upon U2 controller sequencing successfully,
U2_RESET goes high.
To initiate a reverse power-down sequence, install a
shunt across jumper JU8 or JU13. When all the IN_ voltages monitored by U2 (U2_IN1–U2_IN5) have dropped
below their undervoltage threshold, U2_REM output
goes high, thereby allowing U1_OUT_ to commence
sequencing down. U2_REM connects to
U1_ EN_HOLD (through SW1-2) to force U1 controller
to stay on even if U1_EN and U1_SHDN are pulled low
during a daisy-chain operation.
Switch SW1-3 connects U1 and U2 open-drain FAULT
outputs together, resulting in a fast power-down of all
inputs when a fault condition occurs on any of the
inputs or when FAULT is manually pulled low by
installing a shunt across jumpers JU9 or JU14.
Table 12. SW1 Switch Functions
SW1
DESIGNATION
SWITCH
POSITION
SHDN
On
U1 and U2 SHDN inputs connected and controlled by one signal.
REV_SEQ
On
Connects U2_REM to U1_EN_HOLD. Reverse-sequence U2_OUT and then U1_OUT when a
shunt is installed across jumper JU8 or JU13.
FAULT
On
Connects UI_FAULT and U2_FAULT. All outputs power down simultaneously during fault
conditions.
SEQ
On
Connects U1_RESET to U2_EN. Sequences U1 OUT_ and then U2 OUT_.
EV KIT OPERATION
Table 13. Jumper Configuration for Daisy-Chain Operation
JUMPER
8
SHUNT
POSITION
EV KIT OPERATION
JU2
1-2
JU7
Not installed
U1_EN_HOLD controlled by U2_REM
U1 controllers enabled at U1_VCC = 3.3V (DC-DC mode)
JU8, JU13
Not installed
U1_SHDN and U2_SHDN = high
JU9, JU14
Not installed
U1_FAULT and U2_FAULT connected together
JU11
Not installed
JU15
1-2
U2_EN controlled by switch SW1-4
U2_EN_HOLD = high
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MAX16050 Evaluation Kit
Evaluates: MAX16050/MAX16051
Figure 2a. MAX16050 EV Kit Schematic (Sheet 1 of 2)
_______________________________________________________________________________________
9
Evaluates: MAX16050/MAX16051
MAX16050 Evaluation Kit
Figure 2b. MAX16050 EV Kit Schematic (Sheet 2 of 2)
10
______________________________________________________________________________________
MAX16050 Evaluation Kit
Evaluates: MAX16050/MAX16051
Figure 3. MAX16050 EV Kit Component Placement Guide—Component Side
______________________________________________________________________________________
11
Evaluates: MAX16050/MAX16051
MAX16050 Evaluation Kit
Figure 4. MAX16050 EV Kit PCB Layout—Component Side
12
______________________________________________________________________________________
MAX16050 Evaluation Kit
Evaluates: MAX16050/MAX16051
Figure 5. MAX16050 EV Kit PCB Layout—Solder Side
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