- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383152 > ISL6524CB (INTERSIL CORP) Adjustable Precision Shunt Regulator 5-SOT-23 -40 to 125 PDF資料下載
參數(shù)資料
| 型號： | ISL6524CB |
| 廠商： | INTERSIL CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Adjustable Precision Shunt Regulator 5-SOT-23 -40 to 125 |
| 中文描述： | SWITCHING CONTROLLER, 215 kHz SWITCHING FREQ-MAX, PDSO28 |
| 封裝： | PLASTIC, MS-013-AE, SOIC-28 |
| 文件頁數(shù)： | 12/16頁 |
| 文件大?。?/td> | 445K |
| 代理商： | ISL6524CB |
12
FN9015.3
April 18, 2005
Compensation Break Frequency Equations
Figure 12 shows an asymptotic plot of the DC-DC converter’s
gain vs. frequency. The actual Modulator Gain has a high gain
peak dependent on the quality factor (Q) of the output filter,
which is not shown in Figure 12. Using the above guidelines
should yield a Compensation Gain similar to the curve plotted.
The open loop error amplifier gain bounds the compensation
gain. Check the compensation gain at F
P2
with the capabilities
of the error amplifier. The Closed Loop Gain is constructed on
the log-log graph of Figure 12 by adding the Modulator Gain (in
dB) to the Compensation Gain (in dB). This is equivalent to
multiplying the modulator transfer function to the compensation
transfer function and plotting the gain.
The compensation gain uses external impedance networks
Z
FB
and Z
IN
to provide a stable, high bandwidth (BW) overall
loop. A stable control loop has a gain crossing with
-20dB/decade slope and a phase margin greater than
45 degrees. Include worst case component variations when
determining phase margin.
Component Selection Guidelines
Output Capacitor Selection
The output capacitors for each output have unique
requirements. In general the output capacitors should be
selected to meet the dynamic regulation requirements.
Additionally, the PWM converter requires an output capacitor
to filter the current ripple. The load transient for the
microprocessor core requires high quality capacitors to
supply the high slew rate (di/dt) current demands.
PWM Output Capacitors
Modern microprocessors produce transient load rates
above 1A/ns. High frequency capacitors initially supply the
transient current and slow the load rate-of-change seen by
the bulk capacitors. The bulk filter capacitor values are
generally determined by the ESR (effective series
resistance) and voltage rating requirements rather than
actual capacitance requirements.
High frequency decoupling capacitors should be placed as
careful not to add inductance in the circuit board wiring that
could cancel the usefulness of these low inductance
components. Consult with the manufacturer of the load on
specific decoupling requirements.
Use only specialized low-ESR capacitors intended for
switching-regulator applications for the bulk capacitors. The
bulk capacitor’s ESR determines the output ripple voltage and
the initial voltage drop following a high slew-rate transient’s
edge. An aluminum electrolytic capacitor’s ESR value is
related to the case size with lower ESR available in larger
case sizes. However, the equivalent series inductance (ESL)
of these capacitors increases with case size and can reduce
the usefulness of the capacitor to high slew-rate transient
loading. Unfortunately, ESL is not a specified parameter. Work
with your capacitor supplier and measure the capacitor’s
impedance with frequency to select a suitable component. In
most cases, multiple electrolytic capacitors of small case size
perform better than a single large case capacitor.
Linear Output Capacitors
The output capacitors for the linear regulators provide
dynamic load current. Thus capacitors C
OUT2
, C
OUT3
, and
C
OUT4
should be selected for transient load regulation.
PWM Output Inductor Selection
The PWM converter requires an output inductor. The output
inductor is selected to meet the output voltage ripple
requirements and sets the converter’s response time to a
load transient. The inductor value determines the converter’s
ripple current and the ripple voltage is a function of the ripple
current. The ripple voltage and current are approximated by
the following equations:
Increasing the value of inductance reduces the ripple
current and voltage. However, large inductance values
increase the converter’s response time to a load transient.
One of the parameters limiting the converter’s response to
a load transient is the time required to change the inductor
current. Given a sufficiently fast control loop design, the
ISL6524 will provide either 0% or 100% duty cycle in
response to a load transient. The response time is the time
interval required to slew the inductor current from an initial
F
Z1
-----------------------------------
=
F
Z2
+
2
R1
R3
C3
------------------------------------------------------
=
F
P1
2
π
R
2
C1
C2
+
----------------------
×
×
------------------------------------------------------
=
F
P2
2
R
3
C3
-----------------------------------
=
100
80
60
40
20
0
-20
-40
-60
F
P1
F
Z2
10M
1M
100K
10K
1K
100
10
OPEN LOOP
ERROR AMP GAIN
F
Z1
F
P2
F
LC
F
ESR
COMPENSATION
GAIN
G
FREQUENCY (Hz)
MODULATOR
GAIN
FIGURE 12. ASYMPTOTIC BODE PLOT OF CONVERTER GAIN
CLOSED LOOP
GAIN
20
P
–
VP
log
20
R1
log
I
V
-------------------------------
V
–
S
V
IN
---------------
×
=
V
OUT
I
ESR
×
=
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ISL6524CBZ-T | VRM8.5 PWM and Triple Linear Power System Controller |
| ISL6524CBZA | VRM8.5 PWM and Triple Linear Power System Controller |
| ISL6524CBZA-T | VRM8.5 PWM and Triple Linear Power System Controller |
| ISL6524 | Adjustable Precision Shunt Regulator 3-SOT-23 -40 to 85 |
| ISL6524ACB-T | VRM8.5 PWM and Triple Linear Power System Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ISL6524CBT | 制造商:Intersil Corporation 功能描述: |
| ISL6524CB-T | 功能描述:IC CTRLR VRM8.5 PWM TRPL 28-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:電源，ICERA E400，E450 輸入電壓:4.1 V ~ 5.5 V 輸出數(shù):10 輸出電壓:可編程 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:42-WFBGA，WLCSP 供應(yīng)商設(shè)備封裝:42-WLP 包裝:帶卷 (TR) |
| ISL6524CBZ | 功能描述:IC CTLR VRM8.5 PWM TRPL 28-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:控制器，DSP 輸入電壓:4.5 V ~ 25 V 輸出數(shù):2 輸出電壓:最低可調(diào)至 1.2V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:30-TFSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:30-TSSOP 包裝:帶卷 (TR) |
| ISL6524CBZA | 功能描述:IC CTRLR VRM8.5 PWM TRPL 28-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:43 系列:- 應(yīng)用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:48-QFN（7x7） 包裝:管件 |
| ISL6524CBZA-T | 功能描述:IC CTLR VRM8.5 PWM TRPL 28-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:控制器，DSP 輸入電壓:4.5 V ~ 25 V 輸出數(shù):2 輸出電壓:最低可調(diào)至 1.2V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:30-TFSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:30-TSSOP 包裝:帶卷 (TR) |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。