MAX1739EVKIT Maxim Integrated Products, MAX1739EVKIT Datasheet - Page 5

• Manufacturer Part Number: MAX1739EVKIT
• Description: Power Management Modules & Development Tools MAX1739 EVAL KIT MAX1739 EVAL KIT
• Manufacturer: Maxim Integrated Products

Specifications of MAX1739EVKIT

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

There are two methods for communicating with the
MAX1739: through the normal user-interface panel or
through the SMBus commands available from pressing
the MAXSMBUS button. A display pops up that allows
the SMBus protocols, such as Read Byte and Write
Byte, to be executed. To stop normal user-interface exe-
cution so that it does not override the manually set val-
ues, turn off the timer by unchecking the Automatic
Read checkbox.
The SMBus dialog boxes accept numeric data in binary,
decimal, or hexadecimal. Hexadecimal numbers should
be prefixed by $ or 0x. Binary numbers must be exactly
eight digits.
Jumper JU1 sets the MAX1739 to either ADC mode or
SMBus mode. There are two possible settings in ADC
mode: negative scale and positive scale. In negative
scale ADC mode, JU1 = 1-2, the brightness of the lamp
decreases as the voltage on the CTL/SCL pin increases.
In positive scale ADC mode, JU1 = 1-3, the brightness
of the lamp increases as the voltage on the CTL/SCL pin
increases. In SMBus mode, JU1 = 1-4, the SMBus inter-
face is enabled on the MAX1739. Refer to the
MAX1739/MAX1839 IC data sheet for more information.
Jumper JU2 connects the CRF/SDA pin to VL either
directly (position 1-2) or through a 10kΩ resistor (posi-
tion 2-3). This is a pullup resistor for the SMBus data sig-
nal.
In ADC mode, the CRF/SDA pin sets the reference input
voltage for the analog-to-digital converter (ADC).
Connecting this pin directly to V
input voltage to 5.3V. To use a voltage other than 5.3V,
leave JU2 open and apply an external voltage to the
CRF/SDA pad.
Table 1. SH/SUS and SHMD Register Truth Table
Detailed Description of Hardware
SH /SUS
X
0
0
1
1
_______________________________________________________________________________________
Simple SMBus Commands
SHMD2
0
0
0
0
1
L
sets the reference
Jumper JU1
Jumper JU2
MAX1739 Evaluation System/
SHMD1
X
X
0
1
X
Jumper JU3 sets the voltage on the MINDAC pin. This
voltage sets the digital-to-analog converter’s (DAC’s)
minimum scale output voltage.
In the 1-2 position, MINDAC is connected to VL. In this
position, the lamp is completely off at the minimum
scale. Additionally, the DPWM chopping function is dis-
abled (refer to the MAX1739 IC data sheet).
In the 1-3 position, MINDAC is connected to REF
through a voltage-divider formed by R1 and R2. The
voltage on MINDAC is approximately 1V.
In the 1-4 position, MINDAC is connected directly to
REF. The voltage on MINDAC is 2V.
Jumper JU4, in the 1-2 position, enables the MAX1739
unless the SMBus suspend line (SH/SUS) pulls low.
In the 2-3 position, the MAX1739 is placed into shut-
down mode.
The jumper JU5 must be left open for SMBus operation
to prevent loading to the SMBus data signal.
For ADC mode, the shunt must be installed. This con-
nects the potentiometer R8 to the reference input volt-
age for the ADC (CRF/SDA).
When using this mode, jumper JU6 must be installed in the 1-2
position. This connects the R8 wiper to the CTL/SCL pin.
Adjusting R8 changes the voltage on this pin, which changes
the brightness of the lamp.
Jumper JU6, in the 2-3 position, connects CTL/SCL to VL
through a 10kΩ resistor. This position is for SMBus operation.
The resistor is a pullup resistor for the SMBus clock signal.
Table 2 lists the jumper settings.
SHMD0
X
X
X
0
1
Evaluation Kit
OPERATING MODE
Status1 set
Status1 set
Status1 set
Shutdown
Shutdown
Shutdown
Jumper JU3
Jumper JU4
Jumper JU5
Jumper JU6
Operate
Operate
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