- 您現(xiàn)在的位置：買賣IC網 > PDF目錄384422 > HIP6011 (HARRIS SEMICONDUCTOR) Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor PDF資料下載
參數(shù)資料
| 型號： | HIP6011 |
| 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, PDSO14 |
| 文件頁數(shù)： | 8/9頁 |
| 文件大?。?/td> | 89K |
| 代理商： | HIP6011 |
8
One of the parameters limiting the converter’s response to a
load transient is the time required to change the inductor cur-
rent. Given a sufficiently fast control loop design, the HIP6011
will provide either 0% or 100% duty cycle in response to a
load transient. The response time is the time required to slew
the inductor current from an initial current value to the tran-
sient current level. During this interval the difference between
the inductor current and the transient current level must be
supplied by the output capacitor. Minimizing the response
time can minimize the output capacitance required.
The response time to a transient is different for the applica-
tion of load and the removal of load. The following equations
give the approximate response time interval for application
and removal of a transient load:
where: I
TRAN
is the transient load current step, t
RISE
is the
response time to the application of load, and t
FALL
is the
response time to the removal of load. With a +5V input source,
the worst case response time can be either at the application or
removal of load and dependent upon the output voltage setting.
Be sure to check both of these equations at the minimum and
maximum output levels for the worst case response time.
Input Capacitor Selection
Use a mix of input bypass capacitors to control the voltage
overshoot across the MOSFETs. Use small ceramic capaci-
tors for high frequency decoupling and bulk capacitors to sup-
ply the current needed each time Q1 turns on. Place the small
ceramic capacitors physically close to the MOSFETs and
between the drain of Q1 and the anode of Schottky diode D2.
The important parameters for the bulk input capacitor are the
voltage rating and the RMS current rating. For reliable
operation, select the bulk capacitor with voltage and current rat-
ings above the maximum input voltage and largest RMS cur-
rent required by the circuit. The capacitor voltage rating should
be at least 1.25 times greater than the maximum input voltage
and a voltage rating of 1.5 times is a conservative guideline.
The RMS current rating requirement for the input capacitor of a
buck regulator is approximately 1/2 the DC load current.
For a through hole design, several electrolytic capacitors (Pana-
sonic HFQ series or Nichicon PL series or Sanyo MV-GX or
equivalent) may be needed. For surface mount designs, solid
tantalum capacitors can be used, but caution must be exer-
cised with regard to the capacitor surge current rating. These
capacitors must be capable of handling the surge-current at
power-up. The TPS series available from AVX, and the 593D
series from Sprague are both surge current tested.
MOSFET Selection/Considerations
The HIP6011 requires an N-channel power MOSFET. It
should be selected based upon r
DS(ON)
, gate supply
requirements, and thermal management requirements.
In high-current applications, the MOSFET power dissipation,
package selection and heatsink are the dominant design fac-
tors. The power dissipation includes two loss components;
conduction loss and switching loss. The conduction losses are
the largest component of power dissipation for the MOSFET.
Switching losses also contribute to the overall MOSFET
power loss (see the equations below). These equations
assume linear voltage-current transitions and are approxima-
tions. The gate-charge losses are dissipated by the HIP6011
and don't heat the MOSFET. However, large gate-charge
increases the switching interval, t
SW
, which increases the
upper MOSFET switching losses. Ensure that the MOSFET is
within its maximum junction temperature at high ambient tem-
perature by calculating the temperature rise according to
package thermal-resistance specifications. A separate heat-
sink may be necessary depending upon MOSFET power,
package type, ambient temperature and air flow.
Standard-gate MOSFETs are normally recommended for
use with the HIP6011. However, logic-level gate MOSFETs
can be used under special circumstances. The input voltage,
upper gate drive level, and the MOSFET’s absolute
gate-to-source voltage rating determine whether logic-level
MOSFETs are appropriate.
Figure 9 shows the upper gate drive (BOOT pin) supplied by
a bootstrap circuit from V
CC
. The boot capacitor, C
BOOT
develops a floating supply voltage referenced to the PHASE
pin. This supply is refreshed each cycle to a voltage of V
CC
less the boot diode drop (V
D
) when the lower MOSFET, Q2
turns on. A logic-level MOSFET can only be used for Q1 if
the MOSFET’s absolute gate-to-source voltage rating
exceeds the maximum voltage applied to V
CC
.
Figure 10 shows the upper gate drive supplied by a direct con-
nection to VCC. This option should only be used in converter
systems where the main input voltage is +5VDC or less. The
peak upper gate-to-source voltage is approximately V
CC
less
the input supply. For +5V main power and +12VDC for the
bias, the gate-to-source voltage of Q1 is 7V. A logic-level
MOSFET is a good choice for Q1 under these conditions.
t
RISE
=
L x I
TRAN
V
IN
- V
O
t
FALL
=
L x I
TRAN
V
O
P
COND
= I
O2
x r
DS(ON)
x D
P
SW
=1
2I
O
x V
IN
x t
SW
x F
S
Where: D is the duty cycle = V
O
/ V
IN
,
t
SW
is the switching interval, and
F
S
is the switching frequency.
FIGURE 9. UPPER GATE DRIVE - BOOTSTRAP OPTION
+12V
HIP6011
GND
UGATE
PHASE
BOOT
VCC
+5V OR +12V
C
BOOT
D
BOOT
Q1
D2
NOTE:
V
G-S
≈
V
CC
- V
D
+
-
V
D
+
-
HIP6011
相關PDF資料 |
PDF描述 |
|---|---|
| HIP6012CBZ | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| HIP6012CVZ | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| HIP6012 | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| HIP6012CB | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| HIP6013CBZ | Buck Pulse-Width Modulator (PWM) Controller |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| HIP6011 WAF | 制造商:Harris Corporation 功能描述: |
| HIP6011CB | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| HIP6011CB-T | 制造商:Rochester Electronics LLC 功能描述:STD 14SOIC BUCK PWM WITH OVER VOLTAGE PROTECTION/1.5% - Tape and Reel |
| HIP6012 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| HIP6012_04 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
發(fā)布緊急采購，3分鐘左右您將得到回復。