hip6303cbz-t Intersil Corporation, hip6303cbz-t Datasheet - Page 9

• Manufacturer Part Number: hip6303cbz-t
• Description: Microprocessor Core Voltage Regulator Multiphase Buck Pwm Controller
• Manufacturer: Intersil Corporation

explained above. After this period and a short interval
described above, the PWM outputs are initiated and the
voltage rises in 10.08ms, for a total delay time DT of
10.24ms.
Figure 3 shows the start-up sequence as initiated by a fast
rising 5V supply, V
short rise to the three state level in PWM 1 output during first
32 PWM cycles.
Figure 4 shows the waveforms when the regulator is
operating at 200kHz. Note that the Soft-Start duration is a
function of the Channel Frequency as explained previously.
Also note the pulses on the COMP terminal. These pulses
are the current correction signal feeding into the comparator
input (see the Block Diagram on page 2).
FIGURE 3. START-UP OF 4 PHASE SYSTEM OPERATING AT
FIGURE 4. START-UP OF 4 PHASE SYSTEM OPERATING AT
DELAY TIME
500kHz
200kHz
DELAY TIME
CC,
applied to the HIP6303. Note the
9
V
IN
V
IN
= 12V
= 12V
PWM 1
OUTPUT
PGOOD
V
5V
V
V COMP
PGOOD
V
5V
V
CORE
CC
CORE
CC
HIP6303
Figure 5 shows the regulator operating from an ATX supply.
In this figure, note the slight rise in PGOOD as the 5V supply
rises.The PGOOD output stage is made up of NMOS and
PMOS transistors. On the rising V
becomes active slightly before the NMOS transistor pulls
“down”, generating the slight rise in the PGOOD voltage.
.
Note that Figure 5 shows the 12V gate driver voltage
available before the 5V supply to the HIP6303 has reached
its threshold level. If conditions were reversed and the 5V
supply was to rise first, the start-up sequence would be
different. In this case the HIP6303 will sense an over-current
condition due to charging the output capacitors. The supply
will then restart and go through the normal Soft-Start cycle.
Fault Protection
The HIP6303 protects the microprocessor and the entire
power system from damaging stress levels. Within the
HIP6303 both Over-Voltage and Over-Current circuits are
incorporated to protect the load and regulator.
Over-Voltage
The VSEN pin is connected to the microprocessor CORE
voltage. A CORE over-voltage condition is detected when
the VSEN pin goes more than 15% above the programmed
VID level.
The over-voltage condition is latched, disabling normal PWM
operation, and causing PGOOD to go low. The latch can
only be reset by lowering and returning V
POR and Soft-Start sequence.
During a latched over-voltage, the PWM outputs will be
driven either low or three state, depending upon the VSEN
input. PWM outputs are driven low when the VSEN pin
detects that the CORE voltage is 15% above the
programmed VID level. This condition drives the PWM
outputs low, resulting in the lower or synchronous rectifier
FIGURE 5. SUPPLY POWERED BY ATX SUPPLY
ATX SUPPLY ACTIVATED BY ATX “PS-ON PIN”
V
IN
= 5V, CORE LOAD CURRENT = 31A
FREQUENCY 200kHZ
CC
, the PMOS device
CC
high to initiate a
12V ATX
SUPPLY
PGOOD
V
5 V ATX
SUPPLY
CORE