- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384422 > HIP6005ACB (HARRIS SEMICONDUCTOR) Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor PDF資料下載
參數(shù)資料
| 型號(hào)： | HIP6005ACB |
| 廠商： | HARRIS SEMICONDUCTOR |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor |
| 中文描述： | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 |
| 文件頁數(shù)： | 6/12頁 |
| 文件大?。?/td> | 153K |
| 代理商： | HIP6005ACB |
2-103
Functional Description
Initialization
The HIP6005A automatically initializes upon receipt of
power. Special sequencing of the input supplies is not
necessary. The Power-On Reset (POR) function continually
monitors the input supply voltages. The POR monitors the
bias voltage at the V
CC
pin and the input voltage (V
IN
) on
the OCSET pin. The level on OCSET is equal to V
IN
less a
fixed voltage drop (see over-current protection). The POR
function initiates soft start operation after both input supply
voltages exceed their POR thresholds. For operation with a
single +12V power source, V
IN
and V
CC
are equivalent and
the +12V power source must exceed the rising V
CC
threshold before POR initiates operation.
Soft Start
The POR function initiates the soft start sequence. An
internal 10
μ
A current source charges an external capacitor
(C
SS
) on the SS pin to 4V. Soft start clamps the error
amplifier output (COMP pin) and reference input (+ terminal
of error amp) to the SS pin voltage. Figure 3 shows the soft
start interval with C
SS
= 0.1
μ
F. Initially the clamp on the error
amplifier (COMP pin) controls the converter’s output voltage.
At t
1
in Figure 3, the SS voltage reaches the valley of the
oscillator’s triangle wave. The oscillator’s triangular
waveform is compared to the ramping error amplifier voltage.
This generates PHASE pulses of increasing width that
charge the output capacitor(s). This interval of increasing
pulse width continues to t
2
. With sufficient output voltage,
the clamp on the reference input controls the output voltage.
This is the interval between t
2
and t
3
in Figure 3. At t
3
the SS
voltage exceeds the DACOUT voltage and the output
voltage is in regulation. This method provides a rapid and
controlled output voltage rise. The PGOOD signal toggles
‘high’ when the output voltage (V
SEN
pin) is within
±
5% of
DACOUT. The 2% hysteresis built into the power good
comparators prevents PGOOD oscillation due to nominal
output voltage ripple.
Over-Current Protection
The over-current function protects the converter from a
shorted output by using the upper MOSFET’s on-resistance,
r
DS(ON)
to monitor the current. This method enhances the
converter’s efficiency and reduces cost by eliminating a
current sensing resistor.
The over-current function cycles the soft-start function in a
hiccup mode to provide fault protection. A resistor (R
OCSET
)
programs the over-current trip level. An internal 200
μ
A current
sink develops a voltage across R
OCSET
that is referenced to
V
IN
. When the voltage across the upper MOSFET (also
referenced to V
IN
) exceeds the voltage across R
OCSET
, the
over-current function initiates a soft-start sequence. The soft-
start function discharges C
SS
with a 10
μ
A current sink and
inhibits PWM operation. The soft-start function recharges C
SS
,
and PWM operation resumes with the error amplifier clamped
to the SS voltage. Should an overload occur while recharging
C
SS
, the soft start function inhibits PWM operation while fully
charging C
SS
to 4V to complete its cycle. Figure 4 shows this
operation with an overload condition. Note that the inductor
current increases to over 15A during the C
SS
charging interval
and causes an over-current trip. The converter dissipates very
little power with this method. The measured input power for the
conditions of Figure 4 is 2.5W.
The over-current function will trip at a peak inductor current
(I
PEAK)
determined by:
I
DS ON
)
where I
OCSET
is the internal OCSET current source (200
μ
A
typical). The OC trip point varies mainly due to the
MOSFETs r
DS(ON)
variations. To avoid over-current tripping
in the normal operating load range, find the R
OCSET
resistor
from the equation above with:
1. Themaximumr
DS(ON)
atthehighestjunctiontemperature.
2. The minimum I
OCSET
from the specification table.
3. Determine I
PEAK
for
where
I is the output inductor ripple current.
,
0V
0V
0V
TIME (5ms/DIV.)
SOFT-START
(1V/DIV.)
OUTPUT
VOLTAGE
(1V/DIV.)
t
2
t
3
PGOOD
(2V/DIV.)
t
1
FIGURE 3. SOFT START INTERVAL
O
S
0A
0V
TIME (20ms/DIV.)
5A
10A
15A
2V
4V
FIGURE 4. OVER-CURRENT OPERATION
I
PEAK
R
---------------------------------------------------
=
I
PEAK
I
OUT MAX
(
)
I
(
)
2
+
>
HIP6005A
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| HIP6005B | Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor |
| HIP6005BCB | Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor |
| HIP6005BCV | Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor |
| HIP6006CBZ | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| HIP6006CBZ-T | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| HIP6005ACB-T | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| HIP6005B | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor |
| HIP6005BCB | 制造商:Rochester Electronics LLC 功能描述:PWM CONTROLLER 3.5 TO 1.3V DAC RANGE,20LD SOIC - Bulk |
| HIP6005BCB WAF | 制造商:Harris Corporation 功能描述: |
| HIP6005BCB-T | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Mode SMPS Controller |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。