- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384529 > ISL88550A (Intersil Corporation) Synchronous Step Down Controller with Sourcing and Sinking LDO Regulator PDF資料下載
參數(shù)資料
| 型號： | ISL88550A |
| 廠商： | Intersil Corporation |
| 英文描述： | Synchronous Step Down Controller with Sourcing and Sinking LDO Regulator |
| 中文描述： | 同步降壓控制器，具有采購和下沉LDO穩(wěn)壓器 |
| 文件頁數(shù)： | 18/25頁 |
| 文件大?。?/td> | 928K |
| 代理商： | ISL88550A |
18
FN6168.0
October 12, 2005
FIGURE 25. DUAL-MODE FEEDBACK DECODER
Setting the Buck Regulator Output (V
OUT
) with a
Resistive Voltage-Divider at FB
The Buck Regulator output voltage can be adjusted from
0.7V to 3.5V using a resistive voltage-divider (Figure 26).
The ISL88550A regulates FB to a fixed reference voltage
(0.7V). The adjusted output voltage is:
Where VFB is 0.7V and
FIGURE 26. SETTING VOUT WTH A RESISTIVE VOLTAGE
DIVIDER
Setting the VTT and VTTR Voltages (LDO)
The Termination Power Supply Output (VTT) can be set by
two different methods. First, the VTT output can be
connected directly to the VTTS input to force VTT to regulate
to V
REFIN
/2. Secondly, VTT can be forced to regulate higher
than V
REFIN
/2 by connecting a resistive divider from VTT to
VTTS. The maximum value for VTT will be the V
VTTI
-
V
DROPOUT
where V
DROPOUT
= I
VTT
× 0.3 typically.
The Termination Reference Voltage (VTTR) will follow
V
REFIN
.
Inductor Selection (Buck)
The switching frequency and inductor operating point
determine the inductor value as follows:
For example: I
LOAD(MAX)
= 12A, V
IN
= 12V, V
OUT
= 2.5V,
SW
= 300kHz, 30% ripple current or LIR = 0.3
Find a low-loss inductor having the lowest possible DC
resistance that fits in the allotted dimensions. Ferrite cores
are often the best choice, although powdered iron is
inexpensive and can work well at 200kHz. The core must be
large enough not to saturate at the peak inductor current
(I
PEAK
):
Most inductor manufacturers provide inductors in standard
values, such as 1.0μH, 1.5μH, 2.2μH, 3.3μH, etc. Also look
for nonstandard values, which can provide a better
compromise in LIR across the input voltage range. If using a
swinging inductor (where the no-load inductance decreases
linearly with increasing current), evaluate the LIR with
properly scaled inductance values.
Input Capacitor Selection (Buck)
The input capacitor must meet the ripple current requirement
(I
RMS
) imposed by the switching currents:
For most applications, non-tantalum chemistry capacitors
(ceramic, aluminum, or OSCON) are preferred due to their
resistance to power-up surge currents typical of systems
with a mechanical switch or connector in series with the
input. If the ISL88550A are operated as the second stage of
a two-stage power conversion system, tantalum input
capacitors are acceptable. In either configuration, choose a
capacitor that has less than 10°C temperature rise at the
RMS input current for optimal reliability and lifetime.
FB
0.1xREF
(0.2V)
2.5V(FIXED)
1.8V(FIXED)
OUT
REF
(2.0V)
TO ERROR
AMPLIFIER
ISL88550A
2
V
R
R
1
V
V
RIPPLE
D
C
FB
OUT
+
+
=
ESR
LOAD
I
RIPPLE
V
R
LIR
×
×
=
PHASE
L
FB
RD
RC
COUT
OUT
Q2
GND
PGND1
LGATE
ISL88550A
(
)
×
(
)
LIR
I
f
V
V
V
V
L
MAX
LOAD
SW
IN
OUT
IN
OUT
×
×
=
(
)
μH
8
=
3
×
A
12
kHz
300
V
12
V
5
×
V
12
V
5
×
L
=
(
)
+
=
2
LIR
1
I
I
MAX
LOAD
PEAK
=
IN
OUT
V
IN
OUT
V
LOAD
I
RMS
I
V
1
V
ISL88550A
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ISL88550AIRZ | Synchronous Step Down Controller with Sourcing and Sinking LDO Regulator |
| ISL88550AIRZ-T | Synchronous Step Down Controller with Sourcing and Sinking LDO Regulator |
| ISL88694 | Octal Transparent D-Type Latches With 3-State Outputs 20-SOIC -40 to 85 |
| ISL88694IH5 | SMBus Accelerator (SMA) |
| ISL88694IH5-TK | SMBus Accelerator (SMA) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ISL88550AEVAL1 | 功能描述:EVALUATION BOARD 1 ISL88550A RoHS:否 類別:編程器，開發(fā)系統(tǒng) >> 過時/停產(chǎn)零件編號 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 傳感器類型:CMOS 成像，彩色（RGB） 傳感范圍:WVGA 接口:I²C 靈敏度:60 fps 電源電壓:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相關(guān)產(chǎn)品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP |
| ISL88550AEVAL1Z | 功能描述:EVALUATION BOARD 1 ISL88550A RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - DC/DC 與 AC/DC（離線）SMPS 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:True Shutdown™ 主要目的:DC/DC，步升 輸出及類型:1，非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):升壓 頻率 - 開關(guān):3MHz 板類型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
| ISL88550AIRZ | 功能描述:電壓模式 PWM 控制器 INTEGRTD DDR PWR CNT RLR 2 8LD 5X5 TQFN RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| ISL88550AIRZ-T | 功能描述:DC/DC 開關(guān)控制器 INTEGRTD DDR PWR CNT RLR 2 8LD 5X5 TQFN RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| ISL88550AIRZ-T7 | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 Integrated DDR Power Controller, 28LD 5x5 TQFN Pb-free, 1K O RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。