参数资料
型号: MAX1677EEE-T
厂商: Maxim Integrated Products
文件页数: 14/16页
文件大小: 0K
描述: IC REG BST SYNC 0.35A DL 16QSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
类型: 升压(升压)
输出类型: 两者兼有
输出数: 2
输出电压: 3.3V 或可调主电源,-28 V ~ 28 V 或可调副电源
输入电压: 0.7 V ~ 5.5 V
PWM 型: 电流模式
频率 - 开关: 300kHz
电流 - 输出: 350mA
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: 带卷 (TR)
供应商设备封装: 16-QSOP
Compact, High-Efficiency, Dual-Output
Step-Up and LCD Bias DC-DC Converter
Use inductors with a ferrite core or equivalent; powder
iron cores are not recommended for use with the
MAX1677 ’ s high switching frequencies. The inductor ’ s
incremental saturation rating ideally should exceed the
selected current limit, however it is generally accept-
able to bias most inductors into saturation by as much
as 20% (although this may reduce efficiency).
For best efficiency, select inductors with resistance no
greater than the internal N-channel FET resistance in
each boost converter (220m ? for the MBC, and 1 ? for
the LCD). The inductor is effectively in series with the
input at all times, so inductor wire losses can be rough-
ly approximated by I IN2 × R L . See Table 4 for a list of
inductor suppliers.
The LCD boost converter (LCD) features selectable
inductor/switch current limit of 350mA or 225mA. The
higher current setting provides the greatest output cur-
rent, while the lower setting allows the smallest inductor
size.
Table 4. Component Suppliers
External Diodes
The MAX1677 ’ s on-chip synchronous rectifier allows
the normally required external Schottky diode to be
omitted from the MBC in designs whose input exceeds
1.4V. In circuits that need to operate below 1.4V (1-cell
inputs for example), connecting a Schottky diode in
parallel with the internal synchronous rectifier (from LX
to POUT) provides the lowest start-up voltage. Suitable
devices are the 1N5817 or MBR0520L, however the
diode current rating need not match the peak switch
current, since most of the current is handled by the on-
chip synchronous rectifier.
Since the LCD boost converter (LCD) does not have
synchronous rectification, an external diode is always
needed. High switching speed demands a high-speed
rectifier. For best efficiency, Schottky diodes such as
the 1N5818 and MBR0530L are recommended. Be
sure that the diode current rating exceeds the peak
current set by LCDPOL, and that the diode voltage rat-
ing exceeds the LCD output voltage. In particularly
cost-sensitive applications, and if the LCD ’ s 225mA
peak current is set, a high-speed silicon signal diode
(such as an 1N4148) may be used instead of a
SUPPLIER
INDUCTORS
Coilcraft: DO and
DT series
Murata: LQH4 and
LQH3C series
Sumida: CD, CDR,
and RCH series
TDK: NLC Series
CAPACITORS
AVX: TPS series
Matsuo:
267 series
Sanyo: OS-CON
and GX series
Sprague: 595D
series
DIODES
Motorola:
MBR0520
Nihon: EC11 FS1
series
PHONE
847-639-6400
814-237-1431
847-956-0666
847-390-4373
803-946-0690
714-969-2591
619-661-6835
603-224-1961
602-303-5454
805-867-2555
FAX
847-639-1469
814-238-0490
847-956-0702
847-390-4428
803-626-3123
714-960-6492
619-661-1055
603-224-1430
602-994-6430
805-867-2698
Schottky diode, but with reduced efficiency.
Input Bypass Capacitors
A low-ESR input capacitor connected in parallel with
the battery will reduce peak currents and input-reflected
noise. Battery bypassing is especially helpful at low input
voltages and with high-impedance batteries (such as
alkaline types). Benefits include improved efficiency
and lower useful end-of-life voltage for the battery.
100μF is typically recommended for 2-cell applications.
Small ceramic capacitors may also be used for light
loads or in applications that can tolerate higher input
ripple. Only one input bypass capacitor is typically
needed for both the MBC and LCD.
Output Filter Capacitors
For most applications, a 100μF, 10V, low-ESR output fil-
ter capacitor is recommended for the MBC output. A
surface-mount tantalum capacitor typically exhibits
30mV ripple when the MBC is stepping up from 1.2V to
3.3V at 100mA. OS-CON and ceramic capacitors offer
lowest ESR, while low-ESR tantalums offer a good bal-
ance between cost and performance.
The LCD output typically exhibits less than 1% peak-to-
peak ripple with 4.7μF of filter capacitance. This can be
either a ceramic or tantalum type, but be sure that the
capacitor voltage rating exceeds the LCD output volt-
age. If the LCD ’ s 225mA peak switch current setting is
used, the designer can choose lower output ripple or
14
______________________________________________________________________________________
相关PDF资料
PDF描述
MAX1678EUA+T IC REG BOOST SYNC 3.3V/ADJ 8UMAX
MAX1679EUA+ IC BATT CHRGR 1CELL LITH 8-UMAX
MAX1681ESA IC REG MULTI CONFIG ADJ 8SOIC
MAX1683EUK-T IC REG SWITCHED CAP DBL SOT23-5
MAX1685EEE-T IC REG BUCK SYNC 3.3V/ADJ 16QSOP
相关代理商/技术参数
参数描述
MAX1677EVKIT 功能描述:电源管理IC开发工具 Evaluation Kit for the MAX1677 RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
MAX1678ESA 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX1678EUA 功能描述:直流/直流开关转换器 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
MAX1678EUA+ 功能描述:直流/直流开关转换器 1-2 Cell 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
MAX1678EUA+T 功能描述:直流/直流开关转换器 1-2 Cell 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