参数资料
| 型号： | ADP3050AR-3.3 |
| 厂商： | Analog Devices Inc |
| 文件页数： | 18/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK 3.3V 1A 8SOIC |
| 标准包装： | 98 |
| 类型： | 降压（降压） |
| 输出类型： | 固定 |
| 输出数： | 1 |
| 输出电压： | 3.3V |
| 输入电压： | 3.6 V ~ 30 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 200kHz |
| 电流 - 输出： | 1A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 8-SO |
| 配用： | ADP3050-EVAL-ND - BOARD EVAL FOR ADP3050 |
I RIPPLE =
12 1 ? 5
47 × 10 ? 6
ADP3050
INVERTING (BUCK BOOST) REGULATOR
The circuit in Figure 29 shows the ADP3050 in a buck-boost
configuration that produces a negative output voltage from a
positive input voltage. This topology looks quite similar to the
buck shown in Figure 28 (except the IC and the output filter are
now referenced to the negative output instead of ground), but
its operation is quite different. For this topology, the feedback
pin is grounded and the GND pin is tied to the negative output,
allowing the feedback network of the IC to regulate the negative
output voltage.
Data Sheet
For the circuit in Figure 29, the maximum ripple current (at the
maximum input voltage) is
× × = 0 . 375 A
200 × 10 3 12 + ? 5
High ripple currents are present in both the input and output
capacitors, and their ripple current ratings must be large
enough to sustain the large switching currents present in this
topology. The capacitors should have a ripple current rating of
at least
L1
47μH
D2
1N4148
C5
100μF
+
I RMS ( C IN , C OUT ) ≈ I OUT ×
V OUT
V IN
(20)
C3
0.22μF
1
2
SWITCH IN 8
BOOST GND 7
The peak current seen by the diode, switch, and inductor is
found by rearranging the load current equation
? V IN + V OUT
1
× I OUT ? + ? ? × I RIPPLE ? ?
I PEAK = ?
(21)
? ? 2
V IN
?
?
D1
1N5818
3
4
BIAS SD 6
FB COMP 5
U1
ADP3050-5
R1
5.1k?
C4
3.3nF
V OUT
?
? ?
The largest peak currents occur at the lowest input voltage. For
this design with a load current of 500 mA
I PEAK = ? ?
× 0 . 5 ? ? + ? ? × 0 . 375 ? ? = 0 . 9 A
SD
12V
V IN
+ C1
C2
–5V AT 0.5A
? 12 + ? 5
? 12
? 1
? ? 2 ?
(22)
GND
22μF
0.01μF
The average current diode is equal to the load current.
I OUT ( MAX ) =
V IN
(18)
V IN × V OUT
(
)
? I SW ( MAX ) ? ?
Figure 29. Inverting (Buck-Boost) Regulator
The design procedure used for the standard buck converter
cannot be used for a buck-boost converter due to fundamental
differences in how the output voltage is generated. The switch
currents in the buck-boost are much higher than the standard
buck converter, thus lowering the available load current. To
calculate the maximum output current for a given maximum
switch current, use the following equation:
×
V IN + V OUT
? ?
? ?
? 2 × f SW × L × V IN + V OUT ?
where I SW(MAX) is the switch current limit rating of the ADP3050,
and V IN is the minimum input voltage. The inductor ripple
current is estimated using the following equation:
An inductor with a current rating 20% greater than 0.9 A
should be used (a rating of at least 1.2 A). Inductors and diodes
with ratings greater than 1 A should always be used, even if
the calculated peak and average currents are lower. This ensures
that start-up and fault conditions do not overstress the
components.
For the buck-boost topology, the input voltage can be less than
the output voltage, such as V IN = 4 V or V OUT = ?5 V, but the
available load current is even lower. The equations given in this
section are valid for input voltages less than and greater than
the output voltage. The voltage seen by the ADP3050 is equal to
the sum of the input and output voltages (the BOOST pin sees
the sum of V IN + 2 × |V OUT |). It is important to ensure that the
maximum voltage rating of these pins is not exceeded.
I RIPPLE =
V IN ( MAX )
L
×
1
f SW
×
V OUT
V IN ( MAX ) + V OUT
(19)
Rev. C | Page 18 of 20
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ADP3050AR-5 | 制造商:Analog Devices 功能描述:Conv DC-DC Single Step Down 3.6V to 30V 8-Pin SOIC N 制造商:Rochester Electronics LLC 功能描述:HIGH VOLTAGE STEP DOWN SWITCHING REG. - Bulk 制造商:Analog Devices 功能描述:IC SWITCHING REGULATOR |
| ADP3050AR-5-REEL | 制造商:Analog Devices 功能描述:Conv DC-DC Single Step Down 3.6V to 30V 8-Pin SOIC N T/R |
| ADP3050AR-5-REEL7 | 制造商:Analog Devices 功能描述:Conv DC-DC Single Step Down 3.6V to 30V 8-Pin SOIC N T/R 制造商:Analog Devices 功能描述:ANAADP3050AR-5-REEL7 HI VOLT SWCH REG |
| ADP3050AR-REEL | 制造商:Analog Devices 功能描述:Conv DC-DC Single Step Down 3.6V to 30V 8-Pin SOIC N T/R |
| ADP3050AR-REEL7 | 制造商:Analog Devices 功能描述:Conv DC-DC Single Step Down 3.6V to 30V 8-Pin SOIC N T/R 制造商:Rochester Electronics LLC 功能描述:- Tape and Reel |
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