HIP6014 Intersil Corporation, HIP6014 Datasheet - Page 7

• Manufacturer Part Number: HIP6014
• Description: Buck and Synchronous-Rectifier (PWM) Controller and Output Voltage Monitor
• Manufacturer: Intersil Corporation

Remove input power before changing the output voltage.
Adjusting the output voltage during operation could toggle
the PGOOD signal and exercise the overvoltage protection.
All VID pin combinations resulting in a 0V output setting
activate the Power-On Reset function and disable the gate
drive circuitry. For these specific VID combinations, though,
PGOOD asserts a high level. This unusual behavior has
been implemented in order to allow for operation in dual-
microprocessor systems by AND-ing the PGOOD signals
from the two individual power converters.
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 5 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 5 should be located as close
together as possible. Please note that the capacitors C
and C
Locate the HIP6014 within 3 inches of the MOSFETs, Q
and Q
source connections from the HIP6014 must be sized to
handle up to 1A peak current.
Figure 6 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
FIGURE 5. PRINTED CIRCUIT BOARD POWER AND
HIP6014
O
2
. The circuit traces for the MOSFETs’ gate and
each represent numerous physical capacitors.
PHASE
UGATE
LGATE
PGND
GROUND PLANES OR ISLANDS
Q
V
Q
RETURN
IN
2
1
7
D
2
C
IN
L
O
C
O
V
OUT
IN
SS
1
HIP6014
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 7 highlights the voltage-mode control loop for a
synchronous-rectified buck converter. The output voltage
(V
amplifier (Error Amp) output (V
oscillator (OSC) triangular wave to provide a pulse-width
modulated (PWM) wave with an amplitude of V
PHASE node. The PWM wave is smoothed by the output filter
(L
O
OUT
C
FIGURE 7. VOLTAGE-MODE BUCK CONVERTER
FIGURE 6. PRINTED CIRCUIT BOARD SMALL SIGNAL
SS
SS
V
and C
OSC
) is regulated to the Reference voltage level. The error
OSC
HIP6014
O
).
GND
COMPARATOR
COMPENSATION DESIGN
LAYOUT GUIDELINES
ERROR
AMP
DETAILED COMPENSATION COMPONENTS
V
HIP6014
E/A
PWM
Z
+
-
FB
-
+
COMP
BOOT
PHASE
V
C
C
CC
1
REFERENCE
BOOT
C
DACOUT
+
CC
2
+12V
-
R
2
DRIVER
DRIVER
Z
decoupling between V
E/A
C
IN
D
VCC
1
) is compared with the
BOOT
FB
Z
FB
PHASE
as close as practical
(PARASITIC)
V
C
Q
Q
+V
IN
3
1
2
L
Z
R
IN
O
IN
1
L
IN
R
O
ESR
C
C
3
O
at the
O
V
OUT
CC
V
OUT
V
and
OUT