DC786A Linear Technology, DC786A Datasheet - Page 5

• Manufacturer Part Number: DC786A
• Description: LTC4260CGN 200W Positive 48V Hot Swap Controller With Current And Voltage Monitoring (req DC590)
• Manufacturer: Linear Technology
• Series: -r

Specifications of DC786A

• Main Purpose: Power Management, Hot Swap Controller
• Embedded: No
• Utilized Ic / Part: LTC4260
• Primary Attributes: 200W, 36 ~ 72 V
• Secondary Attributes: I²C Interface
• Kit Application Type: Power Management
• Application Sub Type: Hot-Swap Controller
• Kit Contents: Quick Eval Software
• Lead Free Status / Rohs Status: Not applicable / Not applicable

The Fixed option (Figure 3A) shows the data byte in
hex for registers E, F, and G and displays the calculated
Vdd sense, Source voltage, and ADIN values using the
following equations:
Vdd sense = Sense(data) * SenseScale mV
Source voltage = Source(data) * SourceScale V
QUICK START PROCEDURE
BASIC OPERATION
Demonstration circuit 786 is easy to set up to evaluate
the performance of the LTC4260CGN.
1.
2.
3.
4.
5.
To permit autonomous operation, verify that
the jumpers are set as follows:
JP1 BD_PRST\: GND
JP2 ON CONFIG: AUTO
With the power off connect the input supply
to +48V INPUT and the output load as shown
in Fig.4
Turn on the power at the input.
Check that the LTC4260 automatically turns
on.
power is applied to the input and available at
the output. If the output voltage is low as
judged by the PWRGD/GPIO divider R7 and
R8, red LED D3 turns on.
The point at which UV deems the input to be
worthy of turn-on and GPIO judges the out-
put to be "good" are mutually exclusive; these
are two different comparators driven by two
different voltage dividers. As configured
there is a narrow range between 43V and
47V where D2 and D3 are on simultaneously.
To convert to I2C control, set the jumpers as
follows:
Green LEDs D1 and D2 show when
ADIN voltage = ADIN(data) * ADINScale V
The Adjusted option allows the user to enter Rs, R1
and R2. The calculated values are shown using the
following equations:
Idd sense = Vdd sense / Rs mA
ADIN full = ADIN voltage * (R1 + R2) / R2 V
6.
JP1 BD_PRST\: GND
JP2 ON CONFIG: I2C
JP3 SDA: COM
JP4 ADR0: LOW
JP5 ADR1: LOW
JP6 ADR2: LOW
JP7 I2C PORT: Connect the DC786A to the
DC590A USB controller board via 14-pin rib-
bon cable and open the QuickEval software
on the PC. Upon first connection, QuickEval
will identify the DC786A and open the
LTC4260 interface. When the interface is
closed, the user is returned to the main
QuickEval program.
In this configuration the LTC4260 defaults to
the off condition.
D4-7 are useful to view the status of the
ALERT\ output and to debug stuck I2C lines.
Under normal conditions D5-7 flicker faintly
and briefly when a communications transac-
tion takes place. When activated, D4
(ALERT\) stays lit until reset by the I2C port.
D4-7 are buffered by Q2-5 so that they do
not load the I2C lines.
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