参数资料
型号: MAX1706EEE+
厂商: Maxim Integrated Products
文件页数: 12/18页
文件大小: 0K
描述: IC REG BOOST ADJ 0.4A 16QSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 100
类型: 升压(升压)
输出类型: 可调式
输出数: 1
输出电压: 2.5 V ~ 5.5 V
输入电压: 0.7 V ~ 5.5 V
频率 - 开关: 260kHz ~ 340kHz
电流 - 输出: 400mA
同步整流器:
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-SSOP(0.154",3.90mm 宽)
包装: 管件
供应商设备封装: 16-QSOP
产品目录页面: 1410 (CN2011-ZH PDF)
1- to 3-Cell, High-Current, Low-Noise,
Step-Up DC-DC Converters with Linear Regulator
POUT
Q
D
LOGIC HIGH
IFB*
P
Q
POUT
IREF*
R
Q
LX
R
P
S
N
LX
ICS
IFB*
S
Q
N
IREF*
CURRENT-
LIMIT LEVEL
OSC
PGND
CURRENT-
LIMIT LEVEL
R
PGND
*SEE FIGURE 1
Figure 3. Simplified PWM Controller Block Diagram
current limit for the MAX1705, and 950mA (max) for the
MAX1706. During PWM operation, the circuit operates
with a continuous inductor current.
Synchronized PWM Operation
The MAX1705/MAX1706 can also be synchronized to a
200kHz to 400kHz frequency by applying an external
clock to CLK/SEL. This allows the user to set the har-
monics, to avoid IF bands in wireless applications. The
synchronous rectifier is also active during synchronized
PWM operation.
Low-Power PFM Operation
Pulling CLK/SEL low places the MAX1705/MAX1706 in
low-power standby mode. During standby mode, PFM
operation regulates the output voltage by transferring a
fixed amount of energy during each cycle, and then
modulating the switching frequency to control the
power delivered to the output. The devices switch only
as needed to service the load, resulting in the highest
possible efficiency at light loads. Output current capa-
bility in PFM mode is 140mA (from 2.4V input to 3.3V
output). The output is regulated at 1.3% above the
PWM threshold.
During PFM operation, the error comparator detects
output voltage falling out of regulation and sets a
flip-flop, turning on the n-channel MOSFET switch
(Figure 4). When the inductor current ramps to the PFM
mode current limit (435mA) and stores a fixed amount
of energy, the current-sense comparator resets a flip-
flop. The flip-flop turns off the n-channel switch and
turns on the p-channel synchronous rectifier. A second
flip-flop, previously reset by the switch’s “on” signal,
inhibits the error comparator from initiating another
*SEE FIGURE 1
Figure 4. Controller Block Diagram in PFM Mode
cycle until the energy stored in the inductor is dumped
into the output filter capacitor and the synchronous rec-
tifier current ramps down to 70mA. This forces opera-
tion with a discontinuous inductor current.
Synchronous Rectifier
The MAX1705/MAX1706 feature an internal 270m ? ,
p-channel synchronous rectifier to enhance efficiency.
Synchronous rectification provides a 5% efficiency
improvement over similar nonsynchronous step-up
regulators. In PWM mode, the synchronous rectifier is
turned on during the second half of each cycle. In PFM
mode, an internal comparator turns on the synchronous
rectifier when the voltage at LX exceeds the step-up
converter output, and then turns it off when the inductor
current drops below 70mA.
Linear Regulator
The internal low-dropout linear regulator steps down the
output from the step-up converter and reduces switching
ripple. It is intended to power noise-sensitive analog cir-
cuitry, such as low-noise amplifiers and IF stages in cel-
lular phones and other instruments, and can deliver up to
200mA. However, in practice, the maximum output cur-
rent is further limited by the current available from the
boost converter and by the voltage differential between
OUT and LDO. Use a 22μF capacitor with a 1 ? or less
equivalent series resistance (ESR) at the output for sta-
bility (see the Linear Regulator Region of Stable C6 ESR
vs. Load Current graph in the Typical Operating
Characteristics ). When the MAX1705/1706 are activated
by logic control (ONA, ONB ), the linear regulator (LDO)
remains off until the step-up converter (POUT) goes into
12
______________________________________________________________________________________
相关PDF资料
PDF描述
HSC22DREF-S13 CONN EDGECARD 44POS .100 EXTEND
MAX1706EEE IC REG BOOST ADJ 0.4A 16QSOP
GMM22DTKN-S288 CONN EDGECARD 44POS .156 EXTEND
HMC22DREF-S13 CONN EDGECARD 44POS .100 EXTEND
MAX1705EEE IC REG BOOST ADJ 0.85A 16QSOP
相关代理商/技术参数
参数描述
MAX1706EEE+ 功能描述:直流/直流开关转换器 1-3 Cell Step-Up w/Linear Regulator RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1706EEE+T 功能描述:直流/直流开关转换器 1-3 Cell Step-Up w/Linear Regulator RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1706EEE-T 功能描述:直流/直流开关转换器 1-3 Cell Step-Up w/Linear Regulator RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX17073ETJ+ 功能描述:直流/直流开关转换器 TFT-LCD Step-Up DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX17073ETJ+T 功能描述:直流/直流开关转换器 TFT-LCD Step-Up DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT