HIP6005 INTERSIL [Intersil Corporation], HIP6005 Datasheet - Page 7

• Manufacturer Part Number: HIP6005
• Description: Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor
• Manufacturer: INTERSIL [Intersil Corporation]

during operation could toggle the PGOOD signal and
exercise the overvoltage protection.
The DAC function is a precision non-inverting summation
amplifier shown in Figure 5. The resistor values shown are
only approximations of the actual precision values used.
Grounding any combination of the VID pins increases the
DACOUT voltage. The ‘open’ circuit voltage on the VID pins
is the band gap reference voltage, 1.26V.
Application Guidelines
Layout Considerations
As in any high frequency switching converter, layout is very
important. Switching current from one power device to another
can generate voltage transients across the impedances of the
interconnecting bond wires and circuit traces. These
interconnecting impedances should be minimized by using
wide, short printed circuit traces. The critical components
should be located as close together as possible using ground
plane construction or single point grounding.
FIGURE 6. PRINTED CIRCUIT BOARD POWER AND
VID4
VID3
VID2
VID1
VID0
HIP6005
PHASE
FIGURE 5. DAC FUNCTION SCHEMATIC
UGATE
10.7k
21.5k
3.6k
2.7k
5.4k
12k
GROUND PLANES OR ISLANDS
REFERENCE
1.26V
BAND GAP
12k
2.9k
+
-
1.7k
DAC
V
Q1
RETURN
D2
IN
DACOUT
7
C
IN
FB
L
O
+
-
C
O
ERROR
AMPLIFIER
V
OUT
COMP
HIP6005
Figure 6 shows the critical power components of the
converter. To minimize the voltage overshoot the
interconnecting wires indicated by heavy lines should be part
of ground or power plane in a printed circuit board. The
components shown in Figure 6 should be located as close
together as possible. Please note that the capacitors C
C
HIP6005 within 3 inches of the MOSFET, Q1. The circuit
traces for the MOSFETs gate and source connections from
the HIP6005 must be sized to handle up to 1A peak current.
Figure 7 shows the circuit traces that require additional
layout consideration. Use single point and ground plane
construction for the circuits shown. Minimize any leakage
current paths on the SS PIN and locate the capacitor, C
close to the SS pin because the internal current source is
only 10 A. Provide local V
GND pins. Locate the capacitor, C
to the BOOT and PHASE pins.
Feedback Compensation
Figure 8 highlights the voltage-mode control loop for a buck
converter. The output voltage (V
Reference voltage level. The error amplifier (Error Amp)
output (V
triangular wave to provide a pulse-width modulated (PWM)
wave with an amplitude of V
PWM wave is smoothed by the output filter (L
The modulator transfer function is the small-signal transfer
function of V
Gain and the output filter (L
break frequency at F
the modulator is simply the input voltage (V
peak-to-peak oscillator voltage V
Modulator Break Frequency Equations
F
O
LC
FIGURE 7. PRINTED CIRCUIT BOARD SMALL SIGNAL
C
SS
each represent numerous physical capacitors. Locate the
SS
=
-------------------------------------- -
2
HIP6005
E/A
GND
L
1
) is compared with the oscillator (OSC)
OUT
O
LAYOUT GUIDELINES
C
/V
O
E/A
LC
BOOT
PHASE
V
C
CC
. This function is dominated by a DC
BOOT
and a zero at F
+12V
CC
O
IN
F
ESR
and C
decoupling between VCC and
C
at the PHASE node. The
D1
VCC
OUT
=
BOOT
OSC
-------------------------------------------- -
2
O
) is regulated to the
), with a double pole
+V
.
ESR
IN
as close as practical
Q1
ESR C
D2
IN
1
. The DC Gain of
L
) divided by the
O
O
C
and C
O
O
IN
O
V
).
ss
OUT
and