max5059auit Maxim Integrated Products, Inc., max5059auit Datasheet - Page 18

• Manufacturer Part Number: max5059auit
• Description: Parallelable, Secondary-side Synchronous Rectifier Driver And Feedback-generator Controller Ics
• Manufacturer: Maxim Integrated Products, Inc.

Parallelable Secondary-Side Synchronous Rectifier
Driver and Feedback-Generator Controller ICs
9) Select a value for R
Use the remote-sense amplifier (RSA in Figure 1) to
directly sense the voltage across the load, compensat-
ing for voltage drops in PC board tracks or load con-
nection wires. The remote-sense amplifier is a
unity-gain amplifier with sufficient bandwidth to not
interfere with the normal operation of the voltage-con-
trol loop. Direct sensing of the output voltage is possi-
ble if the output voltage is between 0.5V to 2.5V. Figure
Figure 12. Remote-Sense Amplifier Connection for V OUT > 2.5V (or any Other Arbitrary Voltage)
18
3.3V:
R
Select the nearest 1% value.
R
When margining is not used, substitute R
in step 8 and go to step 9.
______________________________________________________________________________________
2
2
= 21.882kΩ.
= 21.8kΩ.
R
50μA
I
REF
2
=
R
V
1
OUT
1
Remote-Sense Amplifier
= 19.1kΩ
and calculate R
V
E/A
IREF
-
V
IREF
R
1
COMPV
I
INV
REF
2
13
14
12
for V
12
for R
C28
OUT
eq
=
R12
11 shows this configuration. Figure 12 shows the use of
the remote-sense amplifier with a voltage-divider. The
remote-sense amplifier has an input bias current of
100µA. The impedance of R1 and R2 must be kept low
in this configuration to avoid excessive errors in the out-
put-voltage set point.
When multiple power modules are providing power to
the same load, the load current must be shared equally
to provide the best reliability and thermal distribution.
The MAX5058/MAX5059 contain circuitry that enable
current sharing among paralleled power supplies with-
out requiring an explicit controlling master circuit.
Current sharing is accomplished by connecting togeth-
er the current-share bus pins (SFP and SFN) of all par-
alleled power supplies (see Figure 13), thus creating a
current-force/share bus. The voltage level on this differ-
ential bus is proportional to the output current of the
power supply that has the highest current compared to
the other supplies. The number of power supplies that
can be paralleled with this method is limited only by
practical considerations.
VSO
15
V
V
OUT
IREF
= 1 +
= ( 50μA )
(
RSA
R1
R2
✕
)
R12
✕
V
IREF
VSP
VSN
17
16
R1
R2
V
OUT
Current Sharing