參數(shù)資料
型號(hào): LTC1703CG
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: Synchronous 8-Bit Up/Down Binary Counters 24-PDIP 0 to 70
中文描述: 5 A DUAL SWITCHING CONTROLLER, 750 kHz SWITCHING FREQ-MAX, PDSO28
封裝: 0.209 INCH, PLASTIC, SSOP-28
文件頁(yè)數(shù): 12/36頁(yè)
文件大?。?/td> 343K
代理商: LTC1703CG
12
LTC1703
current limits or QB dies trying to save the load. This
behavior provides maximum protection against overvolt-
age faults at the output, while allowing the circuit to re-
sume normal operation when the fault is removed. The
overvoltage protection circuit can optionally be set to latch
the output off permanently (see the Overvoltage Fault
section).
The MIN comparator (see Block Diagram) trips whenever
FB is more than 5% below 800mV and immediately forces
the switch duty cycle to 90% to bring the output voltage
back into range. It releases when FB is within the 5%
window. MIN is disabled when the soft-start or current
limit circuits are active—the only two times that the
output should legitimately be below its regulated value.
Notice that the FB pin is the virtual ground node of the
feedback amplifier. A typical compensation network does
not include local DC feedback around the amplifier, so that
the DC level at FB will be an accurate replica of the output
voltage, divided down by R1 and R
B
(Figure 3). However,
the compensation capacitors will tend to attenuate AC
signals at FB, especially with low bandwidth type 1 feed-
back loops. This creates a situation where the MIN and
MAX comparators do not respond immediately to shifts in
the output voltage, since they monitor the output at FB.
Maximizing feedback loop bandwidth will minimize these
delays and allow MIN and MAX to operate properly. See
the Feedback Loop/Compensation section.
SHUTDOWN/SOFT-START
Each half of the LTC1703 has a RUN/SS pin. The RUN/SS
pins perform two functions: when pulled to ground, each
shuts down its half of the LTC1703, and each acts as a
conventional soft-start pin, enforcing a maximum duty
cycle limit proportional to the voltage at RUN/SS. An
internal 3.5
μ
A current source pull-up is connected to each
RUN/SS pin, allowing a soft-start ramp to be generated
with a single external capacitor to ground. The 3.5
μ
A
current sources are active even when the LTC1703 is shut
down, ensuring the device will start when any external
pull-down at RUN/SS is released. Either side can be shut
down without affecting the operation of the other side. If
both sides are shut down at the same time, the LTC1703
goes into a micropower sleep mode, and quiescent cur-
rent drops typically below 50
μ
A. Entering sleep mode also
resets the FAULT latch, if it was set.
Each RUN/SS pin shuts down its half of the LTC1703 when
it falls below about 0.5V (Figure 4). Between 0.5V and
about 1V, that half is active, but the maximum duty cycle
2.5V
2.5V
1.0V
0V
5V
0V
V
OUT
V
RUN/SS
4.5V
RUN/SS CONTROLS
DUTY CYCLE
MIN COMPARATOR ENABLED
RUN/SS CONTROLS
DUTY CYCLE
START-UP
NORMAL OPERATION
CURRENT LIMIT
1703 F04
COMP CONTROLS DUTY CYCLE
LTC1703 ENABLED
0.5V
Figure 4. Soft-Start Operation in Start-Up and Current Limit
APPLICATIOU
W
U
U
相關(guān)PDF資料
PDF描述
LTC1704 Synchronous 8-Bit Up/Down Binary Counters 24-SOIC 0 to 70
LTC1704B Synchronous 8-Bit Up/Down Binary Counters 24-SOIC 0 to 70
LTC1705 Dual 550kHz Synchronous Switching Regulator Controller with 5-Bit VID and 150mA LDO
LTC1705EGN Dual 550kHz Synchronous Switching Regulator Controller with 5-Bit VID and 150mA LDO
LTC1710 Synchronous 8-Bit Up/Down Binary Counters 24-PDIP 0 to 70
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1703CG#PBF 功能描述:IC REG SW DUAL SYNC VID 28SSOP 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)
LTC1703CG#TR 制造商:Linear Technology 功能描述:LDO Cntrlr REG CTRLR 0.9V to 2V 28-Pin SSOP T/R
LTC1703CG#TRPBF 功能描述:IC REG SW DUAL SYNC VID 28SSOP 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
LTC1703IG 功能描述:IC REG SW DL SYNC W/VID 28-SSOP RoHS:否 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
LTC1703IG#PBF 功能描述:IC REG SW DUAL SYNC VID 28SSOP 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