参数资料
型号: ISL6420AIAZ-TK
厂商: Intersil
文件页数: 19/21页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM VM 20-QSOP
标准包装: 1
PWM 型: 电压模式
输出数: 1
频率 - 最大: 1.4MHz
占空比: 100%
电源电压: 4.5 V ~ 28 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 20-SSOP(0.154",3.90mm 宽)
包装: 标准包装
其它名称: ISL6420AIAZ-TKDKR
ISL6420A
greater than the maximum input voltage and a voltage
rating of 1.5 x is a conservative guideline. The RMS
current rating requirement for the input capacitor of a
buck regulator is approximately 1/2 the DC load current.
Equation 14 shows a more specific formula for
determining the input ripple:
Schottky Selection
Rectifier D 2 is a clamp that catches the negative
inductor swing during the dead time between turning off
the lower MOSFET and turning on the upper MOSFET.
The diode must be a Schottky type to prevent the
parasitic MOSFET body diode from conducting. It is
I RMS = I MAX ? ( D – D )
2
(EQ. 14)
acceptable to omit the diode and let the body diode of
the lower MOSFET clamp the negative inductor swing,
For a through hole design, several electrolytic capacitors
(Panasonic HFQ series or Nichicon PL series or Sanyo
MV-GX or equivalent) may be needed. For surface mount
designs, solid tantalum capacitors can be used, but
caution must be exercised with regard to the capacitor
surge current rating. These capacitors must be capable
of handling the surge-current at power-up. The TPS
series available from AVX, and the 593D series from
Sprague are both surge current tested.
MOSFET Selection/Considerations
The ISL6420A requires 2 N-Channel power MOSFETs.
These should be selected based upon r DS(ON) , gate
supply requirements, and thermal management
requirements.
In high-current applications, the MOSFET power
dissipation, package selection and heatsink are the
dominant design factors. The power dissipation includes
two loss components; conduction loss and switching loss.
The conduction losses are the largest component of
power dissipation for both the upper and the lower
MOSFETs. These losses are distributed between the two
MOSFETs according to duty factor (see Equations 15 and
16). Only the upper MOSFET has switching losses, since
the Schottky rectifier clamps the switching node before
the synchronous rectifier turns on.
but efficiency will drop one or two percent as a result.
The diode's rated reverse breakdown voltage must be
greater than the maximum input voltage.
P UFET = I O ? r DS ( ON ) ? D + --- I O ? V IN ? t sw ? f sw
P LFET = I O ? r DS ( ON ) ? ( 1 – D )
2
2 1
2
(EQ. 15)
(EQ. 16)
Where D is the duty cycle = Vo/VIN, t SW is the switching
interval, and f SW is the switching frequency.
These equations assume linear voltage-current
transitions and do not adequately model power loss due
the reverse recovery of the lower MOSFET’s body diode.
The gate-charge losses are dissipated by the ISL6420A
and don't heat the MOSFETs. However, large
gate-charge increases the switching interval, t SW which
increases the upper MOSFET switching losses. Ensure
that both MOSFETs are within their maximum junction
temperature at high ambient temperature by calculating
the temperature rise according to package
thermal-resistance specifications. A separate heatsink
may be necessary depending upon MOSFET power,
package type, ambient temperature and air flow.
19
FN9169.4
December 4, 2009
相关PDF资料
PDF描述
ISL6522CVZ-T IC REG CTRLR BST PWM VM 14-TSSOP
ACM08DTMN-S189 CONN EDGECARD 16POS R/A .156 SLD
ISL88001IH16Z-TK IC VOLT SUPERVISOR 1.58V SOT23-3
VE-J4L-EW-F3 CONVERTER MOD DC/DC 28V 100W
ISL88001IH17Z-TK IC VOLT SUPERVISOR 1.67V SOT23-3
相关代理商/技术参数
参数描述
ISL6420AIAZ-TKS2698 制造商:Intersil Corporation 功能描述:PB-FREE SYNC BUCK PWM CONT. W/ 4.5V-28V INPUT,20LD QSOP, T&R - Tape and Reel
ISL6420AIR 制造商:Intersil Corporation 功能描述:VOLT MODE PWM CNTRLR 0.6V TO 27.5V 700MA 20QFN - Rail/Tube
ISL6420AIR-TK 功能描述:IC REG CTRLR BUCK PWM VM 20-QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 V 降压:是 升压:无 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:40-VFQFN 裸露焊盘 包装:带卷 (TR)
ISL6420AIRZ 功能描述:IC REG CTRLR BUCK PWM VM 20-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC(0.154",3.90mm 宽) 包装:带卷 (TR)
ISL6420AIRZS2698 制造商:Intersil Corporation 功能描述:PB-FREE W/ANNEAL SYNC BUCK PWM CONT. WITH 4.5V-28V INPUT,20L - Rail/Tube