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): 11/32頁
文件大?。?/td> 451K
代理商: LTC1539IGW
11
LTC 1538-AUX/LTC 1539
OPERATIO
N
Frequency Synchronization
U
A Phase-Locked Loop (PLL) is available on the LTC1539
to allow the oscillator to be synchronized to an external
source connected to the PLLIN pin. The output of the
phase detector at the PLL LPF pin is also the control input
of the oscillator, which operates over a 0V to 2.4V range
corresponding to –30% to 30% in frequency. When
locked, the PLL aligns the turn-on of the top MOSFET to
the rising edge of the synchronizing signal. When PLLIN
is left open, PLL LPF goes low, forcing the oscillator to
minimum frequency.
Power-On Reset
The POR1 pin is an open drain output which pulls low
when the main regulator output voltage of the LTC1539
first controller is out of regulation. When the output
voltage rises to within 5% of regulation, a timer is started
which releases POR1 after 2
16
(65536) oscillator cycles.
Auxiliary Linear Regulator
The auxiliary linear regulator in the LTC1538-AUX and
LTC1539 controls an external PNP transistor for operation
up to 500mA. A precise internal AUXFB resistive divider is
invoked when the AUXDR pin is above 9.5V to allow
regulated 12V VPP supplies to be easily implemented.
When AUXDR is below 8.5V an external feedback divider
may be used to set other output voltages. Taking the
AUXON pin low shuts down the auxiliary regulator provid-
ing a convenient logic-controlled power supply.
The AUX block can be used as a comparator having its
inverting input tied to the internal 1.19V reference. The
AUXDR pin is used as the output and requires an external
pull-up to a supply of less than 8.5V in order to inhibit the
invoking of the internal resistive divider.
INTV
CC
/EXTV
CC
Power
Power for the top and bottom MOSFET drivers and most
of the other LTC1538-AUX/LTC1539 circuitry is derived
from the INTV
CC
pin. The bottom MOSFET driver supply is
also connected to INTV
CC
. When the EXTV
CC
pin is left
open, an internal 5V low dropout regulator supplies INTV
CC
power. If EXTV
CC
is taken above 4.8V, the 5V regulator is
turned off and an internal switch is turned on to connect
EXTV
CC
to INTV
CC
. This allows the INTV
CC
power to be
derived from a high efficiency external source such as the
output of the regulator itself or a secondary winding, as
described in the Applications Information section.
The 5V/20mA INTV
CC
regulator can be used as a standby
regulator when the two controllers are in shutdown or
when either or both controllers are on. Irrespective of the
signals on the RUN/SS pins, the INTV
CC
pin will follow the
voltage applied to the EXTV
CC
pin when the voltage applied
to the EXTV
CC
pin is taken above 4.8V. The externally
applied voltage is required to be less than the voltage
applied to the V
IN
pin at all times, even when both control-
lers are shut down. This prevents a voltage backfeed
situation from the source applied to the EXTV
CC
pin to the
V
IN
pin. If the EXTV
CC
pin is tied to the first controller’s 5V
output, the nominal INTV
CC
pin voltage will stay in the
guaranteed range of 4.7V to 5.2V.
(Refer to Functional Diagram)
APPLICATIO
S I
FOR
ATIO
U
The basic LTC1539 application circuit is shown in Fig-
ure1. External component selection is driven by the load
requirement and begins with the selection of R
SENSE
. Once
R
SENSE
is known, C
OSC
and L can be chosen. Next, the
power MOSFETs and D1 are selected. Finally, C
IN
and C
OUT
are selected. The circuit shown in Figure 1 can be config-
ured for operation up to an input voltage of 28V (limited by
the external MOSFETs).
W
U
U
R
SENSE
Selection for Output Current
R
SENSE
is chosen based on the required output current.
The LTC1538-AUX/LTC1539 current comparator has a
maximum threshold of 150mV/R
SENSE
and an input com-
mon mode range of SGND to INTV
CC
. The current com-
parator threshold sets the peak of the inductor current,
yielding a maximum average output current I
MAX
equal to
the peak value less half the peak-to-peak ripple current,
I
L
.
相關(guān)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(guān)代理商/技術(shù)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(chǎn)品目錄頁面:1268 (CN2011-ZH PDF) 其它名稱:*LMV331M5*LMV331M5/NOPBLMV331M5CT