19-3418; Rev 1; 8/05
MAX6870 Evaluation Kit/Evaluation System
General Description
The MAX6870 evaluation system (EV system) consists of
a MAX6870 evaluation kit (EV kit) and a Maxim
CMAXQUSB command module. The MAX6870 EEP-
ROM-configurable, multivoltage supply sequencer/super-
visor monitors several voltage-detector inputs, two auxil-
iary inputs, and four general-purpose logic inputs, and
features programmable outputs for highly configurable
power-supply sequencing applications. The evaluation
software runs under Windows
98/2000/XP, providing a
handy user interface to exercise the features of the
MAX6870.
Order the complete EV system (MAX6870EVCMAXQU)
for comprehensive evaluation of the MAX6870 using a
PC. Order the EV kit (MAX6870EVKIT) if the command
module has already been purchased with a previous
Maxim EV system, or for custom use in other µC-based
systems.
This system can also evaluate the MAX6871–MAX6875.
Contact factory for a free sample of MAX6871ETJ,
MAX6872ETJ, MAX6873ETJ, MAX6874ETJ, or
MAX6875ETJ.
♦
Proven PC Board Layout
♦
Complete Evaluation System
♦
Convenient On-Board Test Points
♦
Fully Assembled and Tested
Features
Evaluate: MAX6870–MAX6875
Ordering Information
The MAX6870 EV software is designed for use with the
complete EV system MAX6870EVCMAXQU (includes
CMAXQUSB module together with MAX6870EVKIT). If
the MAX6870 evaluation software will not be used, the
MAX6870EVKIT board can be purchased by itself,
without the CMAXQUSB module.
PART
MAX6870EVKIT
MAX6870EVCMAXQU
TEMP RANGE
0°C to +70°C
0°C to +70°C
INTERFACE TYPE
User supplied
Windows software,
USB
MAX6870 Stand-Alone EV Kit
The MAX6870 EV kit provides a proven PC board layout
to facilitate evaluation of the MAX6870. It must be inter-
faced to appropriate timing signals for proper operation.
Connect power, ground return, and SCL/SDA interface
signals to the breakout header pins (see Figure 9). The
LEDs and load-switching FETs are optional circuits, which
can be powered separately or disabled altogether. Refer
to the MAX6870 data sheet for timing requirements.
PART
MAX6870EVKIT
CMAXQUSB
QTY
1
1
Parts List
DESCRIPTION
MAX6870 evaluation kit
Command module
Component List
DESIGNATION
C1, C2
QTY
2
DESCRIPTION
1µF, 6.3V X7R ceramic capacitors
(0603)
TDK C1608X7R0J105K
0.1µF, 25V X7R ceramic capacitors
(0603)
TDK C1608X7R1E104K
Open (0603)
3-pin headers
Open
8-pin headers
30V, 200mA Schottky diode (SOT23)
Zetex BAT54CTA common cathode
Diodes Incorporated BAT54C
Fairchild BAT54C
General Semiconductor BAT54C
MAX6870 EV System
The MAX6870 evaluation system software runs under
Windows 98/2000/XP on an IBM-compatible PC, inter-
facing to the EV system board through the computer’s
USB port. See the
Quick Start
section for setup and
operating instructions.
C3–C7
C8
JU1–JU8
JU9–JU14
H1–H4
5
0
8
0
4
D1
1
Windows is a registered trademark of Microsoft Corp.
________________________________________________________________
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.
MAX6870 Evaluation Kit/Evaluation System
Evaluate: MAX6870–MAX6875
Component List (continued)
DESIGNATION
LED1–LED4,
LED9, LED12,
LED14, LED15
LED5–LED8,
LED10, LED11,
LED13, LED16
P1
Q1–Q4
QTY
8
DESCRIPTION
Red LEDs (T1-3/4)
DESIGNATION
R1, R2
R3–R18
R19
U1
8
1
4
Green LEDs (T1-3/4)
2 x 10 right-angle receptacle
Logic-level FETs, 2.7A at 30V
(SOT23)
Fairchild FDN359AN
None
None
QTY
2
16
1
1
8
1
DESCRIPTION
100kΩ
±5%
resistors (0805)
1kΩ
±5%
resistors (0805)
100Ω
±5%
resistor (0805)
MAX6870ETJ (32-pin QFN)
Shunts
PC board, MAX6870 EV kit
Component Suppliers
SUPPLIER
Diodes Inc
Fairchild
General Semiconductor
TDK
Zetex USA
PHONE
805-446-4800
888-522-5372
760-804-9258
847-803-6100
631-543-7100
FAX
805-446-4850
Local rep only
760-804-9259
847-390-4405
631-864-7630
WEBSITE
www.diodes.com
www.fairchildsemi.com
www.gensemi.com
www.component.tdk.com
www.zetex.com
Note:
Indicate you are using the MAX6870 when contacting these component suppliers.
Quick Start
Required Equipment
•
•
•
Before you begin, the following equipment is needed:
Maxim MAX6870EVCMAXQU (contains MAX6870
EV kit board and CMAXQUSB module)
Windows 98/2000/XP computer with a spare serial
(COM) port
9-pin I/O extension cable.
4) Install the evaluation software on your computer by
running the INSTALL.EXE program on the disk. The
program files are copied and icons are created for
them in the Windows Start menu.
5) Connect the USB cable between the CMAXQUSB
and the computer. When you plug in the CMAXQUSB
board for the first time, the windows plug-and-play
system detects the new hardware and automatically
runs the Add New Hardware Wizard. (If the Add New
Hardware Wizard does not appear after a minute,
unplug the board from the USB and plug it in again.)
Make certain to specify the search location. Maxim
software designed for CMAXQUSB includes a copy
of the device driver in the installed software directory.
Refer to
Application Note 3601: Troubleshooting
Windows Plug-and-Play and USB for Maxim
Evaluation Kits
for more details.
6) During device driver installation, Windows XP
shows a warning message indicating that the
device driver Maxim uses does not contain a digital
signature. This is not an error condition. It is safe to
proceed with the installation.
7) Start the MAX6870 program by opening its icon in
the Start menu.
Procedure
Do not turn on the power until all connections
are made:
1) Ensure that JU-1-JU-8 are in the 1-2 position.
Jumper sites JU-9-JU-14 are empty. See the
Jumper Function Tables
section.
2) Select 3.3V or 5.0V logic by setting the CMAXQUSB
VDD_SELECT
Jumper.
3) Carefully connect the boards by aligning the 20-pin
header of the MAX6870 EV kit with the 20-pin con-
nector of the CMAXQUSB module. Gently press
them together. The two boards should be flush
against one another.
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MAX6870 Evaluation Kit/Evaluation System
Digital Inputs Tab
8) After the software locates the CMAXQUSB module
and the MAX6870EVKIT board, the software polls
the device status, updating the status bar.
Digital inputs GPI1–GPI4 can be configured for active-
high or active-low logic. When a GPI_ pin is configured
active high, a logic-high level asserts the corresponding
GPI_ condition in the fault register. This fault register sta-
tus is displayed in the status bar.
Evaluate: MAX6870–MAX6875
Detailed Description of Software
Main Window
The evaluation software’s main window shows a block
diagram of the MAX6870, with many clickable features.
Clicking on different parts of the block diagram leads to
different feature tabs. Clicking
Back
returns to the main
window’s block diagram tab.
Configuration register changes made with the GUI are
written when the
Apply
button is clicked. Configuration
of the device may be reread by clicking
Refresh.
Press function key F1 at any time to return to the block
diagram tab sheet. Press function key F2 to pop up a
window displaying registers pertinent to the selected
feature. The software reads the data registers automati-
cally, unless disabled by unchecking
poll inputs every
2s
under the
options
menu.
At startup, the evaluation software reads the device
configuration from the device registers.
Outputs Tab
The PO_ signals assert when a selected combination of
other signals become asserted. Some PO_ signals allow
only a single combination (i.e., a single product term),
while other PO_ signals can be asserted by two different
combinations (i.e., a sum of two product terms). The volt-
age monitors and the watchdog timers are internal sig-
nals. The GPI_ pins are external inputs. Additionally, one
PO_ signal may depend on another PO_.
When a PO_ signal is asserted, several actions can
occur. The corresponding PO_ pin can be driven to a
high or low logic level. The pin driver can be configured
as an open-drain or as a push-pull output. When in push-
pull mode, several system power-supply voltages are
available, including some charge-pump voltages that are
higher than the IN_ voltages.
The user EEPROM pages can optionally be locked out
when the PO_ is asserted.
The manual reset (MR)
input forces the PO_ signal to its
asserted state. A programmable output cannot depend
solely on
MR.
Refer to the
MR
section of the MAX6870
data sheet.
The
MARGIN
signal allows user system testing by forc-
ing the PO_ signal to a logic-high or logic-low state, or
holding the previously determined state. It is generally
expected that
MARGIN
will be high during normal
operation.
Voltage Monitor Tab
The
voltage monitor
tab configures voltage monitor
thresholds, selects the internal or external reference
voltage (if applicable), and displays ADC conversion
results (if applicable).
To configure one of the IN1–IN6 pins as a window com-
parator, first set the primary threshold (A) to the lower
limit, then set the secondary threshold (B) to the upper
limit, and finally, configure the secondary threshold (B)
as an overvoltage detector. When configuring a PO_
output to respond to this fault as a window comparator,
select both the A and the B thresholds.
When a voltage monitor detects the (A) or (B) threshold
is crossed, a fault condition is asserted. This fault regis-
ter status is displayed in the status bar. V2A_ indicates
that IN2 is under its A threshold, V3_B indicates that
IN3 has crossed its B threshold, and V6AB indicates
that IN6 has crossed both its A and B thresholds.
The software uses the
reference voltage
value to cal-
culate the threshold and ADC voltages.
The MAX6870 and MAX6871 include an analog-to-digi-
tal converter (ADC). The software automatically reads
and displays channels selected under
ADC
Conversion Results.
Watchdog Timers Tab
A watchdog timer asserts a fault condition after a peri-
od of time, unless the timer is periodically reset by an
input pin being toggled. This fault register status is dis-
played in the status bar as WD1 or WD2.
During normal operation, an enabled watchdog timer
must be serviced by toggling a GPI pin periodically.
Typically, an external piece of firmware services the
watchdog timer by toggling a GPI pin inside a loop,
and watchdog timer assertion is configured to drive a
PO_ output pin. Any software defect that halts the
firmware then causes the watchdog timer to assert.
The initial timeout period can be set to a longer value to
allow time for software initialization. Alternatively, the
watchdog timer can be held in reset by an optional
clear input.
Refer to the MAX6870 data sheet for more information
about watchdog timer operation.
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MAX6870 Evaluation Kit/Evaluation System
Evaluate: MAX6870–MAX6875
Registers Tab
The
Registers
tab displays the volatile working regis-
ters of the MAX6870. Pressing
Refresh
reads and dis-
plays all register values. Individual register bytes can
be modified by selecting the appropriate grid cell and
typing zero-x prefix (0x) followed by two hexadecimal
digits 0–9/A–F. If
options
menu item
Confirm REG
Write when editing
is checked, a dialog box appears
to confirm each byte written in this manner.
At power-up, the MAX6870 automatically loads its reg-
isters from the configuration EEPROM page. To store
the active register values into the configuration
EEPROM, press
Commit to EEPROM.
The
Re-load
from EEPROM
command sends 88h, rebooting the
MAX6870.
Register values can optionally be stored into a text file
on disk for later retrieval, using the
Load from File
and
Save to File
buttons.
a PC. (There are SCL/SDA pullup resistors on the mod-
ule board.) As a convenience, the module also pro-
vides 5V DC power to U1 through D1, R19, and jumper
JU13. This same 5VDC power supply also powers most
of the EV kit LEDs through jumper JU14.
Programmable outputs PO1–PO4 drive an optional
load-switching demonstration circuit. User-provided
power supplies at IN3–IN6 can drive loads OUT3,
OUT4, OUT5, and OUT6. The circuit can be demon-
strated using LED10, LED11, LED13, LED16 as on-
board loads, or by connecting external loads to the
OUT3–OUT6 oval pads. Q1–Q4 are susceptible to ESD
damage if gates are left floating.
Programmable outputs PO5–PO8 can be configured to
drive LED indicators.
Evaluating the MAX6871–MAX6875
With power off, replace U1 with a MAX6871ETJ,
MAX6872ETJ, MAX6873ETJ, MAX6874ETJ, or
MAX6875ETJ. The software automatically detects the
device type and disables unused features accordingly.
EEPROM Tab
The
EEPROM
tab displays the nonvolatile EEPROM
memory pages of the MAX6870. Pressing
Refresh
reads and displays the selected EEPROM page.
Individual memory bytes can be modified by selecting
the appropriate grid cell and typing zero-x prefix (0x)
followed by two hexadecimal digits 0–9/A–F. If
options
menu item
Confirm EEPROM Write when editing
is
checked, a dialog box appears to confirm each byte
written in this manner.
EEPROM values can optionally be stored into a text file
on disk for later retrieval, using the
Load from File
and
Save to File
buttons.
Diagnostics Window
The diagnostics window is used for factory testing prior
to shipping the evaluation kit. It is not meant for cus-
tomer use.
Jumper Function Tables
Tables 1–13 are jumper function tables.
Table 1. Jumper JU1
JU1 SHUNT
POSITION
Open
1-2
2-3*
FUNCTION
PO1 available for user circuitry.
LED11, LED12, OUT3, Q2 disconnected.
PO1 low lights LED12; Q2 gate is left
floating.
PO1 high turns on Q2, connecting OUT3
to IN3. LED11 lights if IN3 > 3V.
Detailed Description of
Hardware
The MAX6870 (U1) is surrounded by breakout header
pins H1–H4. Two internally generated voltage sources
are bypassed by capacitors C1 and C2. The user
power-supply inputs IN1 and IN3–IN6 are bypassed by
capacitors C3–C7.
If an external reference is used, capacitor site C8
should be loaded with a suitable bypass capacitor.
Otherwise, C8 can be left open.
Connector P1 mates with the CMAXQUSB module,
which enables communication with software running on
*Indicates
default configuration, set by an installed shunt.
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_______________________________________________________________________________________
MAX6870 Evaluation Kit/Evaluation System
Evaluate: MAX6870–MAX6875
Table 2. Jumper JU2
JU2 SHUNT
POSITION
Open
1-2
2-3*
FUNCTION
PO2 available for user circuitry.
LED9, LED10, OUT4, Q1 disconnected.
PO2 low lights LED9; Q1 gate is left
floating.
PO2 high turns on Q1, connecting OUT4
to IN4. LED10 lights if IN4 > 3V.
Table 6. Jumper JU6
JU6 SHUNT
POSITION
Open
1-2*
2-3
FUNCTION
PO6 available for user circuitry.
LED2, LED7 disconnected.
PO6 low lights LED2.
PO6 high lights LED7
(unless configured in open-drain mode
or insufficient pullup source voltage).
*Indicates
default configuration, set by an installed shunt.
*Indicates
default configuration, set by an installed shunt.
Table 3. Jumper JU3
JU3 SHUNT
POSITION
Open
1-2
2-3*
FUNCTION
PO3 available for user circuitry.
LED14, LED13, OUT5, Q3 disconnected.
PO3 low lights LED14; Q3 gate is left
floating.
PO3 high turns on Q3, connecting OUT5
to IN5. LED13 lights if IN5 > 3V.
Table 7. Jumper JU7
JU7 SHUNT
POSITION
Open
1-2*
2-3
FUNCTION
PO7 available for user circuitry.
LED3, LED6 disconnected.
PO7 low lights LED3.
PO7 high lights LED6
(unless configured in open-drain mode
or insufficient pullup source voltage).
*Indicates
default configuration, set by an installed shunt.
*Indicates
default configuration, set by an installed shunt.
Table 4. Jumper JU4
JU4 SHUNT
POSITION
Open
1-2
2-3*
FUNCTION
PO4 available for user circuitry.
LED15, LED16, OUT6, Q4 disconnected.
PO4 low lights LED15; Q4 gate is left
floating.
PO4 high turns on Q4, connecting OUT6
to IN6. LED16 lights if IN6 > 3V.
Table 8. Jumper JU8
JU8 SHUNT
POSITION
Open
1-2*
2-3
FUNCTION
PO8 available for user circuitry.
LED4, LED5 disconnected.
PO8 low lights LED4.
PO8 high lights LED5
(unless configured in open-drain mode
or insufficient pullup source voltage).
*Indicates
default configuration, set by an installed shunt.
*Indicates
default configuration, set by an installed shunt.
Table 5. Jumper JU5
JU5 SHUNT
POSITION
Open
1-2*
2-3
FUNCTION
PO5 available for user circuitry.
LED1, LED8 disconnected.
PO5 low lights LED1.
PO5 high lights LED8
(unless configured in open-drain mode
or insufficient pullup source voltage).
*Indicates
default configuration, set by an installed shunt.
_______________________________________________________________________________________
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