參數(shù)資料
型號(hào): LTC3773EG
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO36
封裝: 5.30 MM, PLASTIC, SSOP-36
文件頁數(shù): 11/32頁
文件大?。?/td> 461K
代理商: LTC3773EG
LTC3773
19
3773fa
age output current IMAX equal to the peak value less half
the peak-to-peak ripple current,
ΔIL.
Allowing a margin for variations in the IC and external
component values yields:
R
mV
I
SENSE
MAX
=
55
The IC works well with values of RSENSE from 0.002Ω to
0.1
Ω.
Slope Compensation and Inductor Peak Current
Slope compensation provides stability in constant fre-
quency architectures by preventing subharmonic oscilla-
tions at duty cycles greater than 50%. It is accomplished
internally by adding a compensating ramp to the inductor
current signal at duty cycles in excess of 40%. Normally,
at the maximum duty cycle, with slope compensation, the
maximum inductor peak current is reduced by more than
50%, reducing the maximum output current at high duty
cycle operation. However, the LTC3773’s slope compensa-
tion recovery is implemented to allow 70% rated inductor
peak current at the maximum duty cycle.
VCC and VDR Power Supplies
Power for the top and bottom MOSFET drivers is derived
from the VDR pin; the internal controller circuitry is derived
from the VCC pin. Under typical operating conditions, the
total current consumption at these two pins should be well
below 100mA. Hence, VDR and VCC can be connected to an
external auxiliary 5V power supply. If an auxiliary supply is
not available, a simple zener diode and a darlington NPN
buffer can be used to power these two pins as shown in
Figure 3. To prevent switching noise from coupling to the
sensitive analog control circuitry, VCC should have a 1F
bypass capacitor, at least, close to the device. The BiCMOS
process that allows the LTC3773 to include large on-chip
MOSFET drivers also limits the maximum VDR and VCC
voltage to 7V. This limits the practical maximum auxiliary
supply to a loosely regulated 7V rail. If VCC drops below
3.9V, LTC3773 goes into undervoltage lockout; if VDR
drops below VCC by more than 1V, the driver outputs are
disabled.
Figure 3. LTC3773 VCC and VDR Power Supplies
Topside MOSFET Driver Supply (CB, DB)
External bootstrap capacitors, CB, connected to the
BOOST pins, supply the gate drive voltages for the topside
MOSFETs. Capacitor CB in Figure 3 is charged though diode
DB from VDR when the SW pin is low. When the topside
MOSFETs turns on, the driver places the CB voltage across
the gate-source of the desired MOSFET. This enhances
the MOSFET and turns on the topside switch. The switch
node voltage, SW, rises to VIN and the BOOST pin follows.
With the topside MOSFET on, the boost voltage is above
the input supply (VBOOST = VDR + VIN). The value of the
boost capacitor CB needs to be 30 to 100 times that of the
total gate charge capacitance of the topside MOSFET(s)
as specied on the manufacturer’s data sheet. The reverse
breakdown of DB must be greater than VIN(MAX).
Regulator Output Voltage
The regulator output voltages are each set by an external
feedback resistive divider carefully placed across the output
capacitor. The resultant feedback signal is compared with
the internal precision 0.6V voltage reference by the error
amplier. The output voltage is given by the equation:
VV
R
OUT
=+
06
1
2
1
.
where R1 and R2 are dened in Figure 1.
+
VOUT
VIN
COUT
CIN
BOOST
TG
SW
BG
VDR
PGND
VCC
L
RSENSE
QT
D1
DB
CB
QB
10
F
10
F
0.1
F
0.1
F
10
100
RZ
2k
VZ
6.8V
Q1
LTC3773
3773 F03
Q1: ZETEX FZT603
VZ: ON SEMI MM5Z6V8ST1
SGND
APPLICATIONS INFORMATION
相關(guān)PDF資料
PDF描述
LTC3801ES6#PBF 1 A SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO6
LTC3803ES6-3 1 A SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO6
LTC3803IS6-3 1 A SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO6
LTC3805HMSE-5#TRPBF SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO10
LTC3805MPMSE-5#PBF SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO10
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3773EG#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(biāo)準(zhǔn)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
LTC3773EG#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:PolyPhase® 標(biāo)準(zhǔn)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
LTC3773EUHF 制造商:Linear Technology 功能描述:DC DC Cntrlr Triple-OUT Sync Step Down 3.3V to 36V Input 38-Pin QFN EP
LTC3773EUHF#PBF 功能描述:IC REG CTRLR BUCK PWM CM 38-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 特色產(chǎn)品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標(biāo)準(zhǔn)包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.5 V ~ 18 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:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR
LTC3773EUHF#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 38-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標(biāo)準(zhǔn)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