参数资料
型号: MAX1964TEEE+
厂商: Maxim Integrated Products
文件页数: 17/30页
文件大小: 0K
描述: IC POWER CTRLR/SEQUENCER 16QSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 100
应用: 电源控制器,序列发生器
输入电压: 4.5 V ~ 28 V
电流 - 电源: 1.25mA
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)
供应商设备封装: 16-QSOP
包装: 管件
Tracking/Sequencing Triple/Quintuple
Power-Supply Controllers
INPUT
D1
MAX1964
4.5V TO 28V
C IN
IN
MAX1965 BST
C1
DH
N H
C BST
L
OUTPUT
1.25V TO 5V*
C2
VL
LX
C OUT
ILIM
DL
N L
R POK
OUT
R COMP
POK
COMP
GND
FB
R1
C COMP1
C COMP2
R2
* FOR OUTPUT VOLTAGES > 5V, SEE " OUTPUT VOLTAGE SELECTION ."
Figure 4. Adjustable Output Voltage
I PEAK = I LOAD ( MAX ) + ?
? I
Find a low-loss inductor having the lowest possible DC
resistance that fits in the allotted dimensions. Ferrite
cores are often the best choice, although powdered
iron is inexpensive and can work well at 200kHz. The
chosen inductor ’ s saturation rating must exceed the
peak inductor current:
? LIR ?
? 2 ? LOAD ( MAX )
Setting the Current Limit
The minimum current-limit threshold must be high
enough to support the maximum load current at the
minimum tolerance level of the current-limit circuit. The
valley of the inductor current occurs at I LOAD(MAX)
minus half of the ripple current:
ture. A good general rule is to allow 0.5% additional
resistance for each ° C of the MOSFET junction temper-
ature rise.
Connect ILIM to VL for the default 250mV (typ) current-
limit threshold. For an adjustable threshold, connect a
resistive-divider from VL to ILIM to GND. The external
adjustment range of 500mV to 2.5V corresponds to a
current-limit threshold of 106mV to 530mV. When
adjusting the current limit, use 1% tolerance resistors
and a 10μA divider current to prevent a significant
increase in the current-limit tolerance.
MOSFET Selection
The MAX1964/MAX1965 ’ s step-down controller drives
two external logic-level N-channel MOSFETs as the cir-
cuit switch elements. The key selection parameters are:
1. On-resistance (R DS(ON) )
> I LOAD ( MAX ) ? ?
? LIR ?
? 2 ? LOAD ( MAX )
V VALLEY ( LOW )
R DS ( ON )
? I
2. Maximum drain-to-source voltage (V DS(MAX) )
3. Minimum threshold voltage (V TH(MIN) )
where R DS(ON) is the on-resistance of the low-side
MOSFET (N L ). For the MAX1964/MAX1965, the mini-
mum current-limit threshold is 190mV (for the typical
250mV default setting). Use the worst-case maximum
value for R DS(ON) from the MOSFET N L data sheet, and
add some margin for the rise in R DS(ON) over tempera-
4. Total gate charge (Q g )
5. Reverse transfer capacitance (C RSS )
The high-side N-channel MOSFET must be a logic-level
type with guaranteed on-resistance specifications at
V GS ≤ 4.5V. Select the high-side MOSFET ’ s on-resis-
tance (R DS(ON) ) so I PEAK ? R DS(ON) ≤ 225mV for the
______________________________________________________________________________________
17
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MAX1964TEEE+ 功能描述:电流和电力监控器、调节器 Track/Seq Trpl/Wuint Power-Supply Ctlr RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
MAX1964TEEE+T 功能描述:电流和电力监控器、调节器 Track/Seq Trpl/Wuint Power-Supply Ctlr RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
MAX1964TEEE-T 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
MAX1965TEEP 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
MAX1965TEEP-T 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel