HIP5600_02 Datasheet, PDF (10/16 Pages) Intersil Corporation – Thermally Protected High Voltage Linear Regulator

HIP5600
The HIP5600 provides an efficient and economical solution
as a start-up supply for applications operating from either AC
(50V_RMS to 280V_RMS) or DC (50V_DC to 400V_DC).
HIP5600
+ 50V_DC TO 400V_DC
BUS
±
RF1 _10µF
RF2
+12V
PWM
V_OUT
FIGURE 14. START UP CIRCUIT
The HIP5600 has on chip thermal protection and output cur-
rent limiting circuitry. These features eliminate the need for
an in-line fuse and a large heat sink.
The HIP5600 can provide up to 40mA for short periods of time
to enable start up of a switch mode power supply‘s control cir-
cuit. The length of time that the HIP5600 will be on, prior to
thermal shutdown, is a function of the power dissipation in the
HIP5600
part, the amount of heat sinking (if any) and the ambient tem-
perature. For example; at 400V_DC with no heat sink, it will
provide 20mA for about 8s, see Figure 8.
Power supply efficiency is improved by turning off the
HIP5600 when the SMPS is up and running. In this application
the output of the HIP5600 would be set via RF1 and RF2 to be
about 9V. The tickler winding would be adjusted to about 12V
to insure that the HIP5600 is kept off during normal operating
conditions.The input current under these conditions is approx-
imately equal to I_BIAS. (See Figure 27).
The HIP5600 can supply a 450µA (±20%) constant current.
(See Figure 15). It makes use of the internal bias network.
See Figure 27 for bias current versus input voltage.
With the addition of a potentiometer and a 10µF capacitor the
HIP5600 will provide a constant current source. I_OUT is given
by Equation 13 in Figure 16.
The HIP5600 can control a P-channel MOSFET or IGPT in a
self-oscillating buck regulator. The circuit shown (Figure 17)
shows the self-oscillating concept with a P-IGBT driving a
dedicated fan load. The output voltage is set by the resistor
combination of RF1, RF2, and RF3. Components C3 and
RF3 impresses the output ripple voltage across RF1 causing
the HIP5600 to oscillate and control the conduction of the
P-IGBT. The start-up protection components limit the initial
surge current in the P-IGBT by forcing this device into its
active region. The snubber circuit is recommended to reduce
the power dissipation of the P-IGBT.
HIP5600
+50V_DC TO +400V_DC
±
0.02µF
+20V_DC TO +400V_DC
I_OUT
LOAD
NOTES:
±
1. V_OUT Floating
2. Fixed 500µA Current Source
FIGURE 15. CONSTANT 450µA CURRENT SOURCE
R1
10µF
I_OUT
I_OUT
= ^1.21V
R1
(EQ. 13)
FIGURE 16. ADJUSTABLE CURRENT SOURCE
72