參數(shù)資料
型號(hào): LTC3816EFE#PBF
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: SWITCHING CONTROLLER, PDSO38
封裝: LEAD FREE, PLASTIC, TSSOP-38
文件頁(yè)數(shù): 20/44頁(yè)
文件大?。?/td> 753K
代理商: LTC3816EFE#PBF
LTC3816
3816f
applicaTions inForMaTion
1. Select fC = feedback crossover frequency =
f
N
OSC
where N is between 5 and 10.
2. At the feedback loop crossover frequency, fC, the loop
gain is unity, therefore the error amplifier gain is:
V
A
V
COMP
SERVO
MOD
LC
SERVO
OUT
=
1
3. Place the error amplifier zero near the LC filter double-
pole frequency:
f
R C
L C
EA ZERO
C
L OUT
(
)
=
1
2
1
2
π
4. The feedforward zero is positioned to give the required
phase boost at the crossover frequency:
f
R C
FF ZERO
FF
(
)
=
1
2
1
π
5. Place the error amplifier pole at 5fC to suppress the
switching noise.
f
R
C C
C
f
EA POLE
C
(
)
=
+
=
1
2
5
1
π
Compensating the switching power supply voltage feed-
back loop is a complex task. The frequency compensation
equations shown in this data sheet were obtained using
some approximations to simplify the calculations. The
compensation values shown in this data sheet are typi-
cal values, optimized for the power components shown
in the circuit. Though similar power components should
suffice, substantially changing even one major power
component or circuit layout may degrade performance
significantly. To verify the calculated component values,
all new circuit designs should be prototyped and tested
for stability.
LINE FEEDFORWARD (LFF)
The LTC3816 incorporates a line feedforward function to
compensate for changes in the line voltage and to simplify
the frequency compensation. On the other hand, with
the line feedforward enabled, the feedback loop has high
modulator gain and is more sensitive to noise pickup.
If the input supply voltage is low (e.g., around 5V) and
well regulated, it is better to disable the LFF function by
shorting the LFF pin to GND. Without LFF, the modulator
gain AMOD(WOLFF) is reduced and the control loop is less
sensitive to noise injection.
AMOD(WOLFF) ≈ 0.85 VIN
If line feedforward is disabled, the control loop needs to
be recompensated in order to account for the reduction
in modulator gain.
DPRSLPVR AND VID DAC SLEW RATE CONTROL
The LTC3816 allows the user to program the VID DAC
voltage transition slew rate by adding a capacitor at the
CSLEW pin. In the IMVP-6.5 mode, CSLEW is internally
pulled up by a 40A current source. Upon a code transition
command, CSLEW is ramped up by the internal current
source. When the capacitor, CSLEW, potential reaches 1V,
the VID DAC output voltage jumps by 1 LSB (12.5mV) and
the controller resets the CSLEW capacitor. This operation
repeats until the DAC reaches its target value. The DAC
voltage slew rate is given by the following equation:
dV
dt
mV
I
C
DAC
CSLEW
SLEW
= 12 5
.
where ICSLEW = 40A.
When the IMVP-6 configuration is selected, the LTC3816
allows two different slew rates as shown in Figure 15.
Toconfigurethenormalslewrate,shortthepinDPRSLPVR
to ground. To configure for a slower slew rate, force the
DPRSLPVRpinpotentialabove1.6V. 25safterthecontrol-
ler detects a low-to-high transition at the DPRSLPVR pin,
相關(guān)PDF資料
PDF描述
LTC3816EFE#TRPBF SWITCHING CONTROLLER, PDSO38
LTC3823IGN#TRPBF 4 A SWITCHING CONTROLLER, PDSO28
LTC3851AEMSE-1#PBF 0.05 A SWITCHING CONTROLLER, 810 kHz SWITCHING FREQ-MAX, PDSO16
LTC3851AIUD-1#TRPBF 0.05 A SWITCHING CONTROLLER, 810 kHz SWITCHING FREQ-MAX, PQCC16
LTC3851AMPMSE-1#PBF 0.05 A SWITCHING CONTROLLER, 810 kHz SWITCHING FREQ-MAX, PDSO16
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3816EUHF#PBF 功能描述:IC DC-DC CTLR S-PHASE 32QFN 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)
LTC3816EUHF#TRPBF 功能描述:IC CONTROLLER S-PHASE 32QFN 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
LTC3816IFE#PBF 功能描述:IC CONTROLLER S-PHASE 38TSSOP 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
LTC3816IFE#TRPBF 功能描述:IC CONTROLLER S-PHASE 38TSSOP 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
LTC3816IUHF#PBF 功能描述:IC CONTROLLER S-PHASE 32QFN 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