PR036A480T012FP Datasheet, PDF (10/13 Pages) Vicor Corporation – PRM™ Regulator

APPLICATION INFORMATION
Vin
VC
VH
PC
SC
TM
SG
IL
OS
NC
NC
ROS
PR _PRM-AL CD _RCD
+IN
+OUT
-IN
-OUT
Factorized
Bus (Vf)
0.4 μH
Vf =
VL
K
+
(I_L•Ro)
K
+IN
+OUT
L
-OUT
TM
VC VTM
O
PC
+OUT
A
D
-IN
-OUT
Figure 16 — Adaptive Loop compensation with soft start using the SC port.
Output Voltage Setting with Adaptive Loop
The equations for calculating R_OS and R_CD to set a VTM output
voltage are:
93100
R_OS =
( ^{VL • 0.8395} ) – 1
(1)
K
R_CD =
91238 _{+ 1}
(2)
R_OS
V_L = Desired load voltage
V_OUT = VTM output voltage
K = VTM transformation ratio
(available from appropriate VTM data sheet)
V_f = PRM output voltage, the Factorized Bus (see Figure 16)
R_O = VTM output resistance
(available from appropriate VTM data sheet)
I_L = Load Current
(actual current delivered to the load)
Output Voltage Trimming (optional)
After setting the output voltage from the procedure above the output
may be margined down (26 Vf min) by a resistor from SC-SG using this
formula:
R_dΩ = ^{10000 Vfd}
V_fs - V_fd
Where V_fd is the desired factorized bus and V_fs is the set factorized bus.
A low voltage source can be applied to the SC port to margin the load
voltage in proportion to the SC reference voltage.
An external capacitor can be added to the SC port as shown in Figure 16
to control the output voltage slew rate for soft start.
Nominal Vout
Range (Vdc)
0.8 ^↔ 1.6
1.1 ^↔ 2.2
1.6 ^↔ 3.3
2.2 ^↔ 4.4
3.3 ^↔ 6.6
4.3 ^↔ 8.8
6.5 ^↔ 13.4
8.7 ^↔ 17.9
13.0 ^↔ 26.9
17.4 ^↔ 36.0
26.0 ^↔ 54.0
VTM
K Factor
1/32
1/24
1/16
1/12
1/8
1/6
1/4
1/3
1/2
2/3
1
Table 2 — 048 input series VTM K factor selection guide
Pre-Regulator Module
PR036A480T012FP
vicorpower.com
Rev. 1.1
Page 10 of 13