參數(shù)資料
型號(hào): mic5236
廠商: Micrel Semiconductor,Inc.
英文描述: Low Quiescent Current μCap LDO Regulator(低靜態(tài)電流μCap技術(shù)低壓差穩(wěn)壓器)
中文描述: 低靜態(tài)電流LDO穩(wěn)壓器μCap(低靜態(tài)電流μCap技術(shù)低壓差穩(wěn)壓器)
文件頁數(shù): 9/12頁
文件大?。?/td> 94K
代理商: MIC5236
November 2000
9
MIC5236
MIC5236
Application Information
The MIC5236 provides all of the advantages of the MIC2950:
wide input voltage range, load dump (positive transients up to
60V), and reversed-battery protection, with the added advan-
tages of reduced quiescent current and smaller package.
Additionally, when disabled, quiescent current is reduced to
0.1
μ
A.
Enable
A low on the enable pin disables the part, forcing the quies-
cent current to less than 0.1
μ
A. Thermal shutdown and the
error flag are not functional while the device is disabled. The
maximum enable bias current is 2
μ
A for a 2.0V input. An open
collector pull-up resistor tied to the input voltage should be set
low enough to maintain 2V on the enable input. Figure 1
shows an open collector output driving the enable pin through
a 200k pull-up resistor tied to the input voltage.
In order to avoid output oscillations, slow transitions from low
to high should be avoided.
Micrel
C
OUT
V
OUT
V
IN
5V
V
ERR
IN
MIC5236
EN
200k
200k
OUT
GND
SHENABLE
ERR
Figure 1. Remote Enable
Input Capacitor
An input capacitor may be required when the device is not
near the source power supply or when supplied by a battery.
Small, surface mount, ceramic capacitors can be used for
bypassing. Larger values may be required if the source
supply has high ripple.
Output Capacitor
The MIC5236 has been designed to minimize the effect of the
output capacitor ESR on the closed loop stability. As a result,
ceramic or film capacitors can be used at the output. Figure 2
displays a range of ESR values for a 10
μ
F capacitor. Virtually
any 10
μ
F capacitor with an ESR less than 3.4
is sufficient
for stability over the entire input voltage range. Stability can
also be maintained throughout the specified load and line
conditions with 1
μ
F film or ceramic capacitors.
0
1
2
3
4
5
5
10
INPUT VOLTAGE (V)
15
20
25
30
O
)
Stable Region
T
J
= 25
°
C
V
OUT
= 10
μ
F
Figure 2. Output Capacitor ESR
Error Detection Comparator Output
The ERR pin is an open collector output which goes low when
the output voltage drops 5% below it
s internally programmed
level. It senses conditions such as excessive load (current
limit), low input voltage, and over temperature conditions.
Once the part is disabled via the enable input, the error flag
output is not valid. Overvoltage conditions are not reflected in
the error flag output. The error flag output is also not valid for
input voltages less than 2.3V.
The error output has a low voltage of 400mV at a current of
200
μ
A. In order to minimize the drain on the source used for
the pull-up, a value of 200k to 1M
is suggested for the error
flag pull-up. This will guarantee a maximum low voltage of
0.4V for a 30V pull-up potential. An unused error flag can be
left unconnected.
NOT
VALID
NOT
VALID
VALID ERROR
Error
Output
Input
Voltage
Output
Voltage
4.75V
0V
0V
5V
1.3V
Figure 3. Error Output Timing
Reverse Current Protection
The MIC5236 is designed to limit the reverse current flow
from output to input in the event that the MIC5236 output has
been tied to the output of another power supply. See the
graphs detailing the reverse current flow with the input
grounded and open.
Thermal Shutdown
The MIC5236 has integrated thermal protection. This feature
is only for protection purposes. The device should never be
intentionally operated near this temperature as this may have
detrimental effects on the life of the device. The thermal
shutdown may become inactive while the enable input is
transitioning a high to a low. When disabling the device via the
enable pin, transition from a high to low quickly. This will
insure that the output remains disabled in the event of a
thermal shutdown.
Current Limit
Figure 4 displays a method for reducing the steady state
short circuit current. The duration that the supply delivers
current is set by the time required for the error flag output to
discharge the 4.7
μ
F capacitor tied to the enable pin. The off
time is set by the 200K resistor as it recharges the 4.7
μ
F
capacitor, enabling the regulator. This circuit reduces the
short circuit current from 280mA to 15mA while allowing for
regulator restart once the short is removed.
相關(guān)PDF資料
PDF描述
MIC5238-1.1BD5 Coaxial Cable; Coaxial RG/U Type:11; Impedance:75ohm; Conductor Size AWG:15; No. Strands x Strand Size:19 x 27; Jacket Material:Fluoropolymer; Conductor Material:Copper; Jacket Color:Black; Leaded Process Compatible:Yes
MIC5238-1.1BM5 Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator
MIC5238-1.3BD5 Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator
MIC5238-1.3BM5 Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator
MIC5238 Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MIC5236_05 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:Low Quiescent Current μCap LDO Regulator
MIC5236-1.8BM 功能描述:IC REG LDO 1.8V .15A 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降(標(biāo)準(zhǔn)):- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制(最小):- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD,TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH
MIC5236-1.8BM TR 功能描述:IC REG LDO 1.8V .15A 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降(標(biāo)準(zhǔn)):- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制(最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD,TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH
MIC5236-1.8BMM 功能描述:IC REG LDO 1.8V .15A 8-MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降(標(biāo)準(zhǔn)):- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制(最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD,TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH
MIC5236-1.8BMM TR 功能描述:IC REG LDO 1.8V .15A 8-MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降(標(biāo)準(zhǔn)):- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制(最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD,TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH