_______________________________________________________________ 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.
MAX5970 Evaluation Kit
Evaluates: MAX5970
19-5220; Rev 0; 4/10
General Description
The MAX5970 evaluation kit (EV kit) is an assembled
and tested PCB used to evaluate the MAX5970 dual
hot-swap controller, which provides protection for sys-
tems with two supply voltages between 0 and 16V. The
on-board microcontroller, which is connected to the PC
through the universal serial bus (USB) port, acts as the
I²C master.
The EV kit also includes WindowsM 2000-, Windows
XPM-, and Windows VistaM-compatible software that
provides a simple user interface for exercising the
MAX5970 features. The program is menu-driven and
offers a graphical user interface (GUI) complete with
control buttons and status displays. The EV kit comes
with the MAX5970ETX+ installed.
Features
S Safely Hot Swaps Two Independent 0 to 16V
Power Supplies After Power-Up
S Windows 2000-, Windows XP-, and Windows Vista
(32-Bit)-Compatible Software
S On-Board Microcontroller to Generate I2C
Commands
S Easy-to-Use, Menu-Driven Software
S USB-PC Connection (Cable Included)
Ordering Information
+Denotes lead(Pb)-free and RoHS compliant.
Component List
Windows, Windows XP, and Windows Vista are registered
trademarks of Microsoft Corp.
PART TYPE
MAX5970EVKIT+ EV Kit
DESIGNATION QTY DESCRIPTION
C1, C3–C10,
C17, C32 11
0.1FF Q10%, 16V X7R ceramic
capacitors (0603)
TDK C1608X7R1C104K
C2, C13, C15, 3
10FF Q20%, 6.3V X5R ceramic
capacitors (0805)
TDK C2012X5R0J106M
C11, C12 2
10pF Q5%, 50V C0G ceramic
capacitors (0603)
TDK C1608C0G1H100J
C14, C16,
C31, C33,
C34
5
1FF Q10%, 25V X5R ceramic
capacitors (0603)
Murata GRM188R61E105K
C18, C19 2
22pF Q5%, 50V C0G ceramic
capacitors (0603)
TDK C1608C0G1H220J
C20 1
0.033FF Q10%, 25V X5R ceramic
capacitor (0603)
Murata GRM188R71E333K
C22, C24,
C26, C28 4
10FF Q10%, 25V X5R ceramic
capacitors (1206)
Murata GRM31CR61E106K
C21, C30,
C25, C29 0Not installed, electrolytic
capacitors (12.5mm x 13.5mm)
DESIGNATION QTY DESCRIPTION
C23, C27 2
4700pF Q10%, 50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H472K
D1, D6–D9,
D14, D15 7 Green LEDs (0603)
D2, D3 2
200mA, 25V Schottky diodes
(3 SOT23)
Fairchild BAT54
D4 1
200mA, 30V Schottky diode
(3 SOT23)
Fairchild BAT54C
D5, D12, D13 3 Red LEDs (0603)
D10, D11 2 4.7V zener diodes (SOD523)
Diodes Inc. BZT52C4V7T
D16, D17 2 1A, 20V Schottky diodes (SMA)
Central Semi CMSH1-20M
GND (x4),
VO1, VO2,
VS1, VS2
8Noninsulated banana-jack
connectors
JU1–JU12 12 3-pin headers
JU13–JU16 4 2-pin headers
MAX5970 Evaluation Kit
Evaluates: MAX5970
2 ______________________________________________________________________________________
Note: Indicate that you are using the MAX5970 when contacting these component suppliers.
Component Suppliers
*EP = Exposed pad.
Component List (continued)
SUPPLIER PHONE WEBSITE
Central Semiconductor Corp. 631-435-1110 www.centralsemi.com
Diodes Incorporated 805-446-4800 www.diodes.com
Fairchild Semiconductor 888-522-5372 www.fairchildsemi.com
Hong Kong X’tals Ltd. 852-35112388 www.hongkongcrystal.com
International Rectifier 310-322-3331 www.irf.com
IRC, Inc. 361-992-7900 www.irctt.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
TDK Corp. 847-803-6100 www.component.tdk.com
DESIGNATION QTY DESCRIPTION
N1, N3 2
30V, 16A n-channel MOSFETs
(8 PQFN)
International Rectifier
IRFH7936PbF
N2, N4 2
60V, 115mA n-channel MOSFETs
(3 SOT23)
Diodes Inc. 2N7002-7-F
P1, P2, P3 3
-50V, 130mA p-channel MOSFETs
(3 SOT23)
Diodes Inc. BSS84
R1, R8, R11,
R18, R19,
R21
0
Not installed, resistors (0603)
R1, R8, R11, R18 are short
(PCB trace); R19, R21 are open
R2 1 220I Q5% resistor (0603)
R3, R26,
R30, R31,
R38–R46,
R48, R49
15 10kI Q5% resistors (0603)
R4 1 2.2kI Q5% resistor (0603)
R5 1 1.5kI Q5% resistor (0603)
R6, R7 2 27I Q5% resistors (0603)
R9, R10 2 4.7kI Q5% resistors (0603)
R12, R13 2 1kI Q1% resistors (0603)
R14, R15,
R23, R25,
R27, R29, R32
7100kI Q5% resistors (0603)
R16, R17 2
0.005I Q1%, 2W sense resistors
(2512)
IRC LRC-LRF-2512LF-01-R005-F
DESIGNATION QTY DESCRIPTION
R20, R22 2 100kI Q1% resistors (0603)
R24, R28,
R33–R36 61kI Q5% resistors (0603)
R37, R47 2 10I Q5% resistors (0603)
TP1–TP17 17 Test points, red
USB 1 USB type-B, right-angle PC-mount
receptacle
U1 1
Dual, hot-swap controller
(36 TQFN-EP*)
Maxim MAX5970ETX+
U2 1 Microcontroller (68 QFN-EP*)
Maxim MAXQ2000-RAX+
U3 1 93C46 type 3-wire EEPROM (8 SO)
U4 1 UART-to-USB converter (32 TQFP)
U5 1 3.3V regulator (5 SOT23)
Maxim MAX8888EZK33+
U6 1 2.5V regulator (5 SC70)
Maxim MAX8511EXK25+
Y1 1
16MHz crystal
Hong Kong X’tals
SSM16000N1HK188F0-0
Y2 1
6MHz crystal
Hong Kong X’tals
SSL60000N1HK188F0-0
— 1 USB high-speed A-to-B cables, 6ft
— 16 Shunts
— 1 PCB: MAX5970 EVALUATION KIT+
MAX5970 Evaluation Kit
Evaluates: MAX5970
_______________________________________________________________________________________ 3
Quick Start
Required Equipment
• MAX5970 EV kit (USB cable included)
• User-supplied Windows 2000, Windows XP, or
Windows Vista PC with a spare USB port
• Two 3.3V to 16V DC power supplies
• Two voltmeters
Note: In the following sections, software-related items
are identified by bolding. Text in bold refers to items
directly from the EV kit software. Text in bold and under-
lined refers to items from the Windows operating system.
Procedure
The MAX5970 EV kit is fully assembled and test-
ed. Follow the steps below to verify board operation.
Caution: Do not turn on power supplies until all con-
nections are completed.
1) Visit www.maxim-ic.com/evkitsoftware to down-
load the latest version of the EV kit software,
5970Rxx.ZIP. Save the EV kit software to a tempo-
rary folder and uncompress the ZIP file.
2) Install the EV kit software on your computer by run-
ning the INSTALL.EXE program inside the tempo-
rary folder. The program files are copied and icons
are created in the Windows Start | Programs menu.
3) Verify that all jumpers (JU1–JU16) are in their default
positions, as shown in Tables 1 and 3.
4) Set the first DC power supply to 5V and connect to
the VS1 and the GND banana-jack connectors on
the EV kit board.
5) Set the second DC power supply to 5V and connect
to the VS2 and the GND banana-jack connectors on
the EV kit board.
6) Connect the first voltmeter to the VO1 and the GND
pads on the EV kit board.
7) Connect the second voltmeter to the VO2 and the
GND pads on the EV kit board.
8) Connect the USB cable from the PC to the EV kit
board. A New Hardware Found window pops up
when installing the USB driver for the first time.
If a window is not seen that is similar to the one
described above after 30s, remove the USB cable
from the board and reconnect it. Administrator privi-
leges are required to install the USB device driver
on Windows.
9) Follow the directions of the Found New Hardware
window to install the USB device driver. Manually
specify the location of the device driver to be
C:\Program Files\MAX5970 (default installation
directory) using the Browse button. During device
driver installation, Windows may show a warning
message indicating that the device driver Maxim
uses does not contain a digital signature. This is
not an error condition and it is safe to proceed
with installation. Refer to the USB_Driver_Help.PDF
document included with the software for additional
information.
10) Turn on the power supplies.
11) Start the EV kit software by opening its icon in the
Start | Programs menu. The EV kit software main
window appears, as shown in Figure 1. Observe as
the program automatically detects the address of
the MAX5970 and starts the main program.
12) Verify that PG1 and PG2 LEDs (D14, D15) are on.
13) Verify that both voltmeters read approximately 5V.
MAX5970 EV Kit Files
FILE DESCRIPTION
INSTALL.EXE Installs the EV kit files on your
computer
MAX5970.EXE Application program
FTD2XX.INF USB driver file
UNINST.INI Uninstalls the EV kit software
USB_Driver_Help.PDF USB driver installation help file
MAX5970 Evaluation Kit
Evaluates: MAX5970
4 ______________________________________________________________________________________
Table 1. Jumper Description (JU1–JU16)
JUMPER SHUNT POSITION DESCRIPTION
JU1
1-2* Powers the MAX5970 using the VS1, VS2 or VIN input supply
2-3 Powers the MAX5970 using the USB or VIN input supply
Open Powers the MAX5970 using the VIN input supply
JU2 — See Table 3 for SMBus/I²C address settings
JU3 — See Table 3 for SMBus/I²C address settings
JU4 1-2* Connects the POL pin of the MAX5970 to DREG through a pullup resistor for
active-high PG_ outputs
2-3 Connects the POL pin of the MAX5970 to GND for active-low PG_ outputs
JU5
1-2* Connects the MODE pin of the MAX5970 to DREG through a pullup resistor for the
channels to operate as a group
2-3 Connects the MODE pin of the MAX5970 to GND for the channels to operate as an
individual hot-swap controller
Open The MODE pin of the MAX5970 is not connected and the channels operate as a group
JU6
1-2*
Connects the PROT pin of the MAX5970 to DREG through a pullup resistor, allowing
ALERT output to be asserted and respective PG_ output deasserted upon critical UV/
OV fault
2-3 Connects the PROT pin of the MAX5970 to GND, allowing ALERT output to be
asserted, and shuts down respective channel upon critical UV/OV fault
Open The PROT pin of the MAX5970 is not connected and ALERT output asserted upon
critical UV/OV fault
JU7 1-2* Configures the LED1 pin of the MAX5970 to drive an LED
2-3 Configures the LED1 pin of the MAX5970 as a GPIO
JU8 1-2* Configures the LED2 pin of the MAX5970 to drive an LED
2-3 Configures the LED2 pin of the MAX5970 as a GPIO
JU9 1-2* Configures the LED3 pin of the MAX5970 to drive an LED
2-3 Configures the LED3 pin of the MAX5970 as a GPIO
JU10 1-2* Configures the LED4 pin of the MAX5970 to drive an LED
2-3 Configures the LED4 pin of the MAX5970 as a GPIO
JU11
1-2* Connects the IRNG2 pin of the MAX5970 to DREG, which sets the channel 2 DAC
current-sense range to 50mV**
2-3 Connects the IRNG2 pin of the MAX5970 to GND, which sets the channel 2 DAC
current-sense range to 25mV**
Open The IRNG2 pin of the MAX5970 is not connected, which sets the channel 2 DAC
current-sense range to 100mV**
JU12
1-2* Connects the IRNG1 pin of the MAX5970 to DREG, which sets the channel 1 DAC
current-sense range to 50mV**
2-3 Connects the IRNG1 pin of the MAX5970 to GND, which sets the channel 1 DAC
current-sense range to 25mV**
Open The IRNG1 pin of the MAX5970 is not connected, which sets the channel 1 DAC
current-sense range to 100mV**
MAX5970 Evaluation Kit
Evaluates: MAX5970
_______________________________________________________________________________________ 5
Detailed Description of Software
The MAX5970 EV kit user interface (Figure 1) is easy to
operate; use the mouse, or press the Tab key to navigate
with the arrow keys. Each of the buttons correspond to
bits in the command and configuration bytes. By click-
ing on them, the correct I²C-compatible write opera-
tion is generated to update the internal registers of the
MAX5970.
Interface
Use the Device Address combo box to select the
MAX5970 I²C address. Checking the Silence I2C
Activity checkbox stops activity between the microcon-
troller and the MAX5970 when the software is idle; other-
wise, the software continuously reads the device's status
and data registers to check that the device is working
properly. These functions create activity on the I²C bus.
Use the Read All Registers button to perform a read
of all of the MAX5970 registers and update the GUI
with each register’s data. The status bar located at the
bottom of the GUI displays the status of the registers
accessed, and the data received or sent.
Configuration
The EV kit software Configuration tab sheet (Figure 1)
displays the Grouping (MODE), Fault Management
(RETRY), Critical Fault Protection (PROT), and
Polarity (POL) general settings at the top, while group-
ing channel-specific settings below. See Table 2 for GUI
control details for each channel. Check the Deglitch
checkboxes located to the right of the OV Critical, OV
Warning, UV Warning, UV Critical, and OC Warning
input controls to enable the deglitch feature for those
settings.
Control and Status
The EV kit software Control / Status tab sheet (Figure 2)
displays the status of each channel, including the volt-
age and current measurements in decimal format. Each
channel can be enabled, regardless of the input voltage,
by configuring the software’s EN1_ and EN2_ combo
boxes, or checking the Force-ON Keys Enable and
Force-ON checkboxes. Check the corresponding Reset
or Hold checkbox to reset or hold the maximum and
minimum voltage measurements and the maximum and
minimum current measurements. Press the Clear Alert
button to clear the alert bit and output signal.
*Default position.
**Refer to the MAX5970 IC data sheet for adjusting the circuit breaker threshold range.
Table 1. Jumper Description (JU1–JU16) (continued)
JUMPER SHUNT POSITION DESCRIPTION
JU13 Open* Sets the ON1 bit to 1 (channel 1 is enabled if EN1 or EN2 is set to 1)
1-2 Sets the ON1 bit to 0 (channel 1 is disabled if EN1 or EN2 is set to 0)
JU14 Open* Sets the ON2 bit to 1 (channel 2 is enabled if EN1 or EN2 is set to 1)
1-2 Sets the ON2 bit to 0 (channel 2 is disabled if EN1 or EN2 is set to 0)
JU15
Open* Connects the HWEN pin of the MAX5970 to DREG, which sets the EN2 bit to 1
on each channel
1-2 Connects the HWEN pin of the MAX5970 to GND, which sets the EN2 bit to 0
on each channel
JU16
Open* Connects the RETRY pin of the MAX5970 to DREG, which configures the part
in auto-retry mode
1-2 Connects the RETRY pin of the MAX5970 to GND, which configures the part in
latch-off mode
MAX5970 Evaluation Kit
Evaluates: MAX5970
6 ______________________________________________________________________________________
Table 2. Software GUI Controls
GUI CONTROL FUNCTION
Voltage-Sense Range Sets the maximum output voltage range to 2V, 4V, 8V, or 16V.
OV Critical Sets the overvoltage critical limit. Enter a decimal value between 0 and 1023 (10-bit binary value).
OV Warning Sets the overvoltage warning limit. Enter a decimal value between 0 and 1023 (10-bit binary value).
UV Warning Sets the undervoltage warning limit. Enter a decimal value between 0 and 1023 (10-bit binary value).
UV Critical Sets the undervoltage critical limit. Enter a decimal value between 0 and 1023 (10-bit binary value).
Max Current-Sense Sets the maximum current-sense range to 25mV, 50mV, or 100mV across the current-sense resistor.
Fast-trip Threshold Sets the fast-trip voltage threshold across the current-sense resistor between 40% and 100% of the
Max Current-Sense setting. Enter a decimal value between 102 and 255 (8-bit binary value).
Fast/Slow Trip Ratio Sets the fast-to-slow trip voltage ratio to 125%, 150%, 175%, or 200% across the current-sense resistor.
OC Warning Sets the overcurrent warning limit. Enter a decimal value between 0 and 1023 (10-bit binary value).
PG Assertion Delay Sets PG_ output signal assertion time delay to 50ms, 100ms, 200ms, or 400ms.
Deglitch Enables deglitching function (two consecutive faults must be detected before the corresponding fault
is asserted).
EN1_ Sets EN1 bit 0 or 1.
EN2_ Sets EN2 bit 0 or 1.
Reset Resets the maximum and minimum voltage or current-detection registers of the corresponding channel.
Hold Locks the maximum and minimum voltage or current-detection registers of the corresponding channel.
Force-ON Keys Enable Enables the Force-ON control register.
Force-ON Enables the channel regardless of the input voltage.
Clear Alert Clears the ALERT bit/deasserts the Alert output.
Stop-Delay Buffer Sets the number of samples that are recorded to a buffer after a shutdown event. Enter a number
between 0 and 50.
Voltage Buffer Enables the voltage buffer.
V Read Mode, 8-Bit Sets the circular-buffer resolution to 8 bits.
V Read Mode, 10-Bit Sets the circular-buffer resolution to 10 bits.
Current Buffer Enables the current buffer.
C Read Mode, 8-Bit Sets the circular-buffer resolution to 8 bits.
C Read Mode, 10-Bit Sets the circular-buffer resolution to 10 bits.
Read Voltage Buffer Reads and displays the voltage-buffer data.
Read Current Buffer Reads and displays the current-buffer data.
SET Enables the LED driver pins.
FLASH Enables the flash on the LED driver pins.
WEAK PULLUP Enables the weak pullup on the LED driver pins.
FLASH PHASE Enables the flash to go out of phase on the LED driver pins.
MAX5970 Evaluation Kit
Evaluates: MAX5970
_______________________________________________________________________________________ 7
Figure 1. MAX5970 EV Kit Software Main Window (Configuration Tab)
MAX5970 Evaluation Kit
Evaluates: MAX5970
8 ______________________________________________________________________________________
Figure 2. MAX5970 EV Kit Software Main Window (Control / Status Tab)
MAX5970 Evaluation Kit
Evaluates: MAX5970
_______________________________________________________________________________________ 9
Circular Buffer
The EV kit software Circular Buffer tab sheet (Figure 3)
allows the user to control and configure the voltage and
current circular buffers for each channel. Each circular
buffer always contains a record of the 50 most-recent
digital measurements. The resolution of these measure-
ments can be set to 8-Bit or 10-Bit. This measurement
record includes the number of post-shutdown event
measurements set by the Stop-Delay Buffer setting, if
the corresponding buffer (Voltage Buffer or Current
Buffer) is set to Run. The corresponding circular buf-
fer stops recording new data if it is set to Stop. The 50
measurements contained in the particular buffer are read
and displayed when the Read Voltage Buffer or Read
Current Buffer buttons are pressed.
Figure 3. MAX5970 EV Kit Software Main Window (Circular Buffer Tab)
MAX5970 Evaluation Kit
Evaluates: MAX5970
10 _____________________________________________________________________________________
LEDs and GPIOs
The MAX5970 has four open-drain LED driver pins that
double as user-programmable GPIOs. Place shunts
across the 1-2 position of jumpers JU7–JU10 and control
the individual LED from the checkboxes (SET, FLASH,
WEAK PULLUP, and FLASH PHASE) within the LEDs
group box. The user can also set the LED driver pin as a
GPIO by placing a shunt in the 2-3 position on jumpers
JU7–JU10 and selecting the Options | GPIO menu item.
Advanced User Interface
There are two methods for communicating with the
MAX5970, through the normal user-interface main
window, or through the I²C commands available by
selecting the Options | Interface (Advanced Users)
menu item. An Advanced User Interface window pops
up with the 2-wire interface tab selected, which allows
the SMBusK/I²C-compatible protocols, such as read
byte and write byte, to be executed. The only SMBus/I²C
compatible protocols used by the MAX5970 are:
1: SMBusWriteByte(addr,cmd,data8)
4: SMBusReadByte(addr,cmd) →data8
The combo and edit boxes accept numeric data in hexa-
decimal and should be prefixed by 0x. See Figure 4 for
an example of this tool.
Figure 4. Example of an SMBusReadByte Operation Using the Advanced User Interface
SMBus is a trademark of Intel Corp.
MAX5970 Evaluation Kit
Evaluates: MAX5970
______________________________________________________________________________________ 11
Detailed Description of Hardware
The MAX5970 EV kit circuit demonstrates the MAX5970
dual-channel hot-swap controller that continually moni-
tors the output current and voltage with an internal 10-bit
ADC. The MAX5970 controls each channel’s n-channel
MOSFET, while monitoring the respective current across
the sense resistor and the output voltage. The EV kit
requires 3V (2.7V + Schottky diode drop) to 16V DC for
normal operation. Each hot-swap channel is configured
to operate with an input voltage as low as 0V.
During a startup cycle, the EV kit’s two channels are
off until the MAX5970’s IN pin voltage exceeds 2.7V
(typ). Once the MAX5970 powers up, it loads the initial
operational settings to the internal registers. If any of the
input channel’s voltage is above the 0.6V undervoltage
threshold, the respective MOSFET is turned on and the
MAX5970 controller monitors the corresponding channel
output current and voltage.
The EV kit features several jumpers to program the ini-
tial operational settings. These settings are maximum
current-sense range for each channel, fault-protection
behavior, power-good output-signal polarity, hardware
enable, fault-management mode, and I²C address for
the controller.
Input Power Sources
The EV kit requires a 3.3V (2.7V + Schottky diode drop)
to 16V input DC source for normal EV kit operation. The
EV kit circuit features jumper JU1 that allows the user
to select one of three methods to provide power to the
MAX5970 IC (U1). If the shunt is connected across pins
1-2 on jumper JU1, the highest voltage source connect-
ed to the VS1, VS2, or VIN inputs supplies power to the
IC. If the shunt is connected across pins 2-3, the highest
voltage between the 3.3V source (derived from the USB
5V supply) and the VIN input supplies power to the IC.
If the shunt is removed, the VIN input supplies power to
U1. Connect a 3.3V to 16V power source across the VIN
and GND pads when using this option. See Table 1 for
jumper JU1 configuration.
Address Selection
The MAX5970’s slave I²C address is configured through
the A0 and A1 pins. The EV kit features jumpers JU2 and
JU3 to configure these pins. The default address is 0110
101 (R/W). See Table 3 for a complete list of addresses.
Verify that the new I²C address matches the address
shown in the software’s Device Address combo box.
*Default position.
Table 3. Shunt Setting for SMBus/I²C Address
SHUNT POSITION
B7 B6 B5 B4 B3 B2 B1 B0
WRITE
ADDRESS
(hex)
READ
ADDRESS
(hex)
JU3
(A1)
JU2
(A0)
Open Open 0 1 1 0 0 0 0 R/W0x60 0x61
Open 1-2 0 1 1 0 0 0 1 R/W0x62 0x63
Open 2-3 0 1 1 0 0 1 0 R/W0x64 0x65
1-2 Open 0 1 1 0 1 0 0 R/W0x68 0x69
1-2* 1-2* 0 1 1 0 1 0 1 R/W0x6A 0x6B
1-2 2-3 0 1 1 0 1 1 0 R/W0x6C 0x6D
2-3 Open 0 1 1 1 0 1 1 R/W0x70 0x71
2-3 1-2 0 1 1 1 0 0 1 R/W0x72 0x73
2-3 2-3 0 1 1 1 0 1 0 R/W0x74 0x75
MAX5970 Evaluation Kit
Evaluates: MAX5970
12 _____________________________________________________________________________________
Hot-Swap Channel Enable
During startup, each hot-swap channel is enabled if the
respective EN2 bit is set to 1 and the ON_ input is high.
The EN2 bit is dependent on the state of the HWEN pin.
If the HWEN pin is pulled to DREG during startup, the
EN2 bit for both channels is set to 1. The EV kit circuit
provides jumper JU15 to configure the HWEN pin. See
Table 1 for jumper JU15 configuration. Connecting the
HWEN pin to GND after startup does not change the
EN2 bit state to 0. However, after startup, the EN2 bit
state for each channel can be changed using the EV kit
GUI software.
Whenever the ON_ pin voltage exceeds the input-voltage
threshold of 0.6V (typ), the ON_ bit is set to 1; otherwise,
it is set to 0. The EV kit circuit is configured to pull up the
ON_ pins to the respective VS_ channel inputs through
resistors R20 or R22. The VS_ input undervoltage thresh-
old can be modified by completing the resistive divider
at each ON_ pin. Use the following equation to select the
value for each ON_ resistor:
UVLO
100k
RVS_ 1
0.6V
Ω
=
−
where VS_UVLO is the desired VS1 or VS2 undervoltage
input and R is the resistor value in ohms for R19 and R21,
respectively.
The EV kit circuit also provides jumpers JU13 and JU14
to connect the respective ON_ pins to GND, thus setting
the ON_ bit to 0. See Table 1 for jumpers JU13 and JU14
configuration.
Refer to the MAX5970 IC data sheet for detailed informa-
tion on enabling and disabling each hot-swap channel.
Grouping Hot-Swap Channels
Depending on the state of the MODE input pin during
startup, the MAX5970 can operate as two independent
hot-swap controllers, or with both controllers together.
The EV kit circuit provides jumper JU5 to configure the
MODE pin. See Table 1 for jumper JU5 configuration.
Reconfiguring jumper JU5 after startup does not change
the initial setting.
PROT and ALERT
The MAX5970 fault-protection mode is programmed dur-
ing startup depending on the PROT pin configuration.
The PROT pin configuration determines whether the PG_
output signal for the channel(s) is cleared or the PG_ out-
put is cleared and the channel(s) shut down. The EV kit
circuit provides jumper JU6 to configure the PROT pin.
See Table 1 for jumper JU6 configuration. Reconfiguring
JU6 after startup does not change the initial setting.
Once a PG_ output is asserted, the ALERT output signal
(red LED D5 or TP11) is always asserted low if any of the
channels’ output voltage is outside the warning or critical
limits, or when an overcurrent-limit fault is detected.
Power-Good Outputs
The MAX5970 power-good (PG_) output signals are
asserted when the output voltage is inside the undervolt-
age and overvoltage programmed limits. The PG_ output
signal polarity is programmed depending on the POL pin
configuration. If the signal polarity is set for active-high
outputs, the respective channel LEDs (D14 and D15) are
turned on when PG_ is asserted. If the signal polarity is
set for active-low outputs, the respective channel’s LED
is turned off when PG_ is asserted. The PG_ output sig-
nals can also be accessed at test points TP5 and TP7.
The EV kit circuit provides jumper JU4 to configure the
POL pin. See Table 1 for jumper JU4 configuration.
FAULT_ Outputs
The MAX5970 FAULT_ output signal is asserted low
whenever a circuit-breaker channel shutdown event
occurs. A circuit-breaker shutdown event occurs when-
ever a fast-trip or slow-trip overcurrent-fault event is
detected. The respective channel LED (D12 and D13)
is turned on when the FAULT_ output is asserted. The
FAULT_ output signals can also be accessed at test
points TP6 and TP8. See the RETRY Configuration sec-
tion for instructions to clear the FAULT_ outputs.
RETRY Configuration
The MAX5970 can be programmed to autoretry or
latch-off mode during startup depending on the RETRY
pin configuration. In autoretry mode, after a shutdown
event, the FAULT_ is cleared and the MAX5970 control-
ler automatically attempts to restart the corresponding
channel after 200ms. In latch-off mode, the channel is
in shutdown. The power at the IN pin must be cycled or
the affected channel’s ON_ pin, EN1 bit, or EN2 bit must
be toggled to restart the latched-off channel and clear
the FAULT_. The EV kit circuit provides jumper JU16 to
configure the RETRY pin. See Table 1 for jumper JU16
configuration. Reconfiguring JU16 after startup does not
change the initial RETRY setting. Refer to the MAX5970
IC data sheet when operating in autoretry mode.
MAX5970 Evaluation Kit
Evaluates: MAX5970
______________________________________________________________________________________ 13
Figure 5a. MAX5970 EV Kit Schematic (Sheet 1 of 3)
MAX5970 Evaluation Kit
Evaluates: MAX5970
14 _____________________________________________________________________________________
Figure 5b. MAX5970 EV Kit Schematic (Sheet 2 of 3)
MAX5970 Evaluation Kit
Evaluates: MAX5970
______________________________________________________________________________________ 15
Figure 5c. MAX5970 EV Kit Schematic (Sheet 3 of 3)
MAX5970 Evaluation Kit
Evaluates: MAX5970
16 _____________________________________________________________________________________
Figure 6. MAX5970 EV Kit Component Placement Guide—
Component Side
Figure 7. MAX5970 EV Kit PCB Layout—Component Side
Figure 8. MAX5970 EV Kit PCB Layout—Inner Layer 2
1.0’’
1.0’’
1.0’’
MAX5970 Evaluation Kit
Evaluates: MAX5970
______________________________________________________________________________________ 17
Figure 9. MAX5970 EV Kit PCB Layout—Inner Layer 3 Figure 10. MAX5970 EV Kit PCB Layout—Solder Side
Figure 11. MAX5970 EV Kit Component Placement Guide—
Solder Side
1.0’’
1.0’’
1.0’’
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.
18 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX5970 Evaluation Kit
Evaluates: MAX5970
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 04/10 Initial release —
