- 您現(xiàn)在的位置：買賣IC網 > PDF目錄377752 > LTC1539IGW (LINEAR TECHNOLOGY CORP) Dual High Efficiency, Low Noise, Synchronous Step-Down Switching Regulators PDF資料下載
參數(shù)資料
| 型號： | LTC1539IGW |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Dual High Efficiency, Low Noise, Synchronous Step-Down Switching Regulators |
| 中文描述： | 2 A SWITCHING CONTROLLER, 400 kHz SWITCHING FREQ-MAX, PDSO36 |
| 封裝： | 0.300 INCH, PLASTIC, SSOP-36 |
| 文件頁數(shù)： | 19/32頁 |
| 文件大?。?/td> | 451K |
| 代理商： | LTC1539IGW |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁當前第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁
19
LTC 1538-AUX/LTC 1539
APPLICATIO
S I
FOR
ATIO
U
stable input to the voltage-controlled oscillator. The filter
components C
LP
and R
LP
determine how fast the loop
acquires lock. Typically, R
LP
= 10k and C
LP
is 0.01
μ
F to 0.1
μ
F.
The low side of the filter needs to be connected to SGND.
W
U
U
The PLL LPF pin can be driven with external logic to obtain
a 1:1.9 frequency shift. The circuit shown in Figure 9 will
provide a frequency shift from f
O
to 1.9f
O
as the voltage on
V
PLLLPF
increases from 0V to 2.4V. Do not exceed 2.4V on
V
PLLLPF
.
SFB1 Pin Operation
When the SFB1 pin drops below its ground referenced
1.19V threshold, continuous mode operation is forced. In
continuous mode, the large N-channel main and synchro-
nous switches are used regardless of the load on the main
output.
In addition to providing a logic input to force continuous
synchronous operation, the SFB1 pin provides a means to
regulate a flyback winding output. The use of a synchro-
nous switch removes the requirement that power must be
drawn from the inductor primary in order to extract power
from the auxiliary winding. With the loop in continuous
mode, the auxiliary output may be loaded without regard
to the primary output load. The SFB1 pin provides a way
to force continuous synchronous operation as needed by
the flyback winding.
The secondary output voltage is set by the turns ratio of the
transformer in conjunction with a pair of external resistors
returned to the SFB1 pin as shown in Figure 4a. The
secondary regulated voltage V
SEC
in Figure 4a is given by:
(
1
119
.
V
N
V
V
R
R
SEC
OUT
≈
+
)
>
+
1
6
5
where N is the turns ratio of the transformer, and V
OUT
is
the main output voltage sensed by SENSE
–
1.
Auxiliary Regulator/Comparator
The auxiliary regulator/comparator can be used as a
comparator or low dropout regulator (by adding an exter-
nal PNP pass device).
When the voltage present at the AUXON pin is greater than
1.19V the regulator/comparator is on. The amplifier is
stable when operating as a low dropout regulator. This
same amplifier can be used as a comparator whose
inverting input is tied to the 1.19V reference.
The AUXDR pin is internally connected to an open drain
MOSFET which can sink up to 10mA. The voltage on
AUXDR determines whether or not an internal 12V resis-
tive divider is connected to AUXFB as described below. A
pull-up resistor is required on AUXDR and the voltage
must not exceed 28V.
Figure 9. Directly Driving PLL LPF Pin
18k
3.3V OR 5V
PLL LPF
2.4V
MAX
LTC1538 F09
Low Battery Comparator
The LTC1539 has an on-chip low battery comparator
which can be used to sense a low battery condition when
implemented as shown in Figure 10. This comparator is
active during shutdown allowing battery charge level
interrogation prior to and after powering up part or all of
the system. The resistor divider R3/R4 sets the compara-
tor trip point as follows:
V
V
R
R
LBITRIP
=
+
119
.
1
4
3
The divided down voltage at the negative (–) input to the
comparator is compared to an internal 1.19V reference. A
20mV hysteresis is built in to assure rapid switching. The
output is an open drain MOSFET and requires a pull-up
resistor. This comparator is active when both the RUN/
SS1 and RUN/SS2 pins are low. The low side of the resistive
divider needs to be connected to SGND.
Figure 10. Low Battery Comparator
–
+
LBI
V
IN
SGND
LBO
R4
R3
1538 F10
1.19V REFERENCE
LTC1539
相關PDF資料 |
PDF描述 |
|---|---|
| LTC1538-AUX | Advanced LinEPIC Self-Calibrating (Self-Cal) Precision Single Operational Amplifier 8-SOIC |
| LTC1539 | Dual High Efficiency, Low Noise, Synchronous Step-Down Switching Regulators |
| LTC1538-AUXIG | ER 1C 1#4 SKT PLUG |
| LTC1538IG-AUX | DIODE ZENER SINGLE 1000mW 15Vz 50mA-Izt 0.05 1uA-Ir 11 PowerDI-123 3K/REEL |
| LTC1538CG-AUX | Dual High Efficiency, Low Noise, Synchronous Step-Down Switching Regulators |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LTC1539IGW#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX |
| LTC1539IGW#TR | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX |
| LTC1539IGW#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX |
| LTC1540CDD | 功能描述:IC COMP NANOPOWER W/REF 8DFN RoHS:否 類別:集成電路 (IC) >> 線性 - 比較器 系列:- 標準包裝:25 系列:- 類型:帶電壓基準 元件數(shù):4 輸出類型:CMOS，開路漏極，TTL 電壓 - 電源，單路/雙路(±):2 V ~ 11 V，±1 V ~ 5.5 V 電壓 - 輸入偏移（最小值）:10mV @ 5V 電流 - 輸入偏壓（最小值）:- 電流 - 輸出（標準）:0.015mA @ 5V 電流 - 靜態(tài)（最大值）:8.5µA CMRR, PSRR（標準）:80dB CMRR，80dB PSRR 傳輸延遲（最大）:12µs 磁滯:50mV 工作溫度:0°C ~ 70°C 封裝/外殼:16-DIP（0.300"，7.62mm） 安裝類型:通孔 包裝:管件 |
| LTC1540CDD#PBF | 功能描述:IC COMP NANOPOWER W/REF 8DFN RoHS:是 類別:集成電路 (IC) >> 線性 - 比較器 系列:- 標準包裝:1 系列:- 類型:通用 元件數(shù):1 輸出類型:CMOS，開路集電極，TTL 電壓 - 電源，單路/雙路(±):2.7 V ~ 5.5 V 電壓 - 輸入偏移（最小值）:7mV @ 5V 電流 - 輸入偏壓（最小值）:0.25µA @ 5V 電流 - 輸出（標準）:84mA @ 5V 電流 - 靜態(tài)（最大值）:120µA CMRR, PSRR（標準）:- 傳輸延遲（最大）:600ns 磁滯:- 工作溫度:-40°C ~ 85°C 封裝/外殼:SC-74A，SOT-753 安裝類型:表面貼裝 包裝:剪切帶 (CT) 產品目錄頁面:1268 (CN2011-ZH PDF) 其它名稱:*LMV331M5*LMV331M5/NOPBLMV331M5CT |
發(fā)布緊急采購，3分鐘左右您將得到回復。