- 您现在的位置：买卖IC网 > PDF目录15514 > MAX1771ESA+ (Maxim Integrated Products)IC REG CTRLR BST PWM 8-SOIC PDF资料下载
参数资料
| 型号： | MAX1771ESA+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 14/16页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BST PWM 8-SOIC |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 100 |
| PWM 型： | 控制器 |
| 输出数： | 1 |
| 频率 - 最大： | 500kHz |
| 占空比： | 92% |
| 电源电压： | 3 V ~ 16.5 V |
| 降压： | 无 |
| 升压： | 是 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 管件 |
| 产品目录页面： | 1410 (CN2011-ZH PDF) |
MAX1771
12V or Adjustable, High-Efficiency,
Low I Q , Step-Up DC-DC Controller
tries to use internal feedback and looks to V+ for its
V IN
4.5V TO 15V
feedback signal. However, since V+ may be greater
than the internally set feedback (12V for the MAX1771),
the IC may think the output is sufficiently high and not
OFF
ON
4
SHDN
2
V+
C1
33 μ F
16V
L1
20 μ H
C2*
1 μ F
D1
1N5819
V OUT
12V
250mA
start. D2 ensures start-up by pulling FB above ground
and forcing the external feedback mode. In a normal
(not AC-coupled) boost circuit, D2 isn’t needed, since
the output and FB rise as soon as input power is
applied.
20 μ H
100 μ F 100 μ F
16V
16V
C5
0.1 μ F
5
REF
MAX1771
1
EXT
8
CS
6
AGND
7
GND
FB
R3 3
28k ?
1%
D2*
1N4148
Q1**
L2*
C3 C4
R1
0.1 ?
NOTE: HIGH-
CURRENT GND
R2
200k ?
1%
*SEE TEXT FOR FURTHER
Transformerless -48V to +5V at 300mA
The circuit in Figure 7 uses a transformerless design to
supply 5V at 300mA from a -30V to -75V input supply.
The MAX1771 is biased such that its ground connec-
tions are made to the -48V input. The IC’s supply volt-
age (at V+) is set to about 9.4V (with respect to -48V)
by a zener-biased emitter follower (Q2). An N-channel
FET (Q1) is driven in a boost configuration. Output reg-
ulation is achieved by a transistor (Q3), which level
shifts a feedback signal from the 5V output to the IC’s
FB input. Conversion efficiency is typically 82%.
NOTE: KEEP ALL TRACES CONNECTED
TO PIN 3 AS SHORT AS POSSIBLE
COMPONENT INFORMATION
**Q1 = MOTOROLA MMFT3055ELT1
L1 + L2 = ONE COILTRONICS CTX20-4
When selecting components, be sure that D1, Q1, Q2,
Q3, and C6 are rated for the full input voltage plus a
reasonable safety margin. Also, if D1 is substituted, it
should be a fast-recovery type with a t rr less than 30ns.
Figure 6. 12V Buck/Boost from a 4.5V to 15V Input
carefully observe the component voltage ratings, since
some components must withstand the sum of the input
and output voltage (27V in this case). The circuit oper-
ates as an AC-coupled boost converter, and does not
change operating modes when crossing from buck to
boost. There is no instability around a 12V input.
Efficiency ranges from 85% at medium loads to about
82% at full load. Also, when shutdown is activated
(SHDN high) the output goes to 0V and sources no cur-
rent. A 1μF ceramic capacitor is used for C2. A larger
capacitor value improves efficiency by about 1% to 3%.
D2 ensures start-up for this AC-coupled configuration
by overriding the MAX1771’s Dual-Mode feature, which
allows the use of preset internal or user-set external
feedback. When operating in Dual-Mode, the IC first
14
R7, R9, C8, and D3 are optional and may be used to
soft start the circuit to prevent excessive current surges
at power-up.
Battery-Powered LCD Bias Supply
The circuit in Figure 8 boosts two cells (2V min) to 24V
for LCD bias or other positive output applications.
Output power is boosted from the battery input, while
V+ voltage for the MAX1771 is supplied by a 5V or 3.3V
logic supply.
5V, 1A Boost Converter
The circuit in Figure 9 boosts a 2.7V to 5.5V input to a
regulated 5V, 1A output for logic, RF power, or PCMCIA
applications. Efficiency vs. load current is shown in the
adjacent graph.
Maxim Integrated
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1744EUB+ | IC REG CTRLR BUCK PWM 10-UMAX |
| MAX1876EEG+ | IC REG CTRLR BUCK PWM VM 24-QSOP |
| MAX1651ESA+ | IC REG CTRLR BUCK PWM 8-SOIC |
| MAX1649ESA+ | IC REG CTRLR BUCK PWM 8-SOIC |
| MAX1714BEEE+ | IC REG CTRLR BUCK PWM CM 16-QSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1771ESA+ | 功能描述:DC/DC 开关控制器 12/Adj V Low IQ Step-Up RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1771ESA+T | 功能描述:DC/DC 开关控制器 12/Adj V Low IQ Step-Up RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1771ESA-T | 功能描述:DC/DC 开关控制器 12/Adj V Low IQ Step-Up RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1771EVKIT-SO | 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX1771 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX1771MJA | 功能描述:DC/DC 开关控制器 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
发布紧急采购，3分钟左右您将得到回复。