命令近义词LTC3442
V IN , V OUT –0.3 to 6V SW1, SW2 Voltage
DC .................................................................–0.3 to 6V Puld &–0.3 to 7V SHDN/SS, –0.3 to 6V Operating Temperature (Note 2).............–40°C to 85°C Maximum Junction Temperature (Note 4)............125°C Storage –65°C to 125°C
ORDER PART NUMBER DE PART MARKING 3442
LTC3442EDE
ABSOLUTE AXI U RATI GS
左脸颊有痣W W W
U PACKAGE/ORDER I FOR ATIO
U
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W (Note 1)
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwi specifications are at T A = 25°C. V IN = V OUT = 3.6V, R T = 64.9k, unless otherwi noted.
PARAMETER CONDITIONS
MIN TYP MAX UNITS
Input Start-Up Voltage ● 2.3 2.4V Output Voltage Adjust Range ● 2.4 5.25V Feedback Voltage ●
1.19
1.22 1.25V Feedback Input Current
V FB = 1.22V
150nA Quiescent Current – Burst Mode Operation V FB = 1.22V, BURST = 0V (Note 3)
3560µA Quiescent Current – Shutdown SHDN = 0V, V OUT = 0V, Not Including Switch Leakage 0.11µA Quiescent Current – Active BURST = V IN (Note 3)6001100µA NMOS Switch Leakage Switches B and C 0.12µA PMOS Switch Leakage Switches A and D 0.13
µA NMOS Switch On Resistance Switches B and C 0.10ΩPMOS Switch On Resistance Switches A and D
0.10
ΩInput Current Limit ●
23A Rever Current Limit
0.5A Burst Mode Operation Current Limit 0.9
A Max Duty Cycle Boost (% Switch C On)●7088
%Buck (% Switch A In)
●100 %
Min Duty Cycle ●0
%Frequency Accuracy ●
570
670770强大的祖国
kHz Error Amp A VOL这的写法
90dB Error Amp Source Current 11µA Error Amp Sink Current 300µA Burst Threshold (Falling)0.88V Burst Threshold (Rising)
1.12
V
T JMAX = 125°C
θJA = 53°C/W 1-Layer Board θJA = 43°C/W 4-Layer Board
θJC = 4.3°C/W
EXPOSED PAD IS PGND (PIN 13)MUST BE SOLDERED TO PCB
121110987
123456
FB V C R LIM V IN V OUT BURST
SHDN/SS
RT SGND SW1PGND SW2
麻酱卷TOP VIEW
13
DE12 PACKAGE
12-LEAD (4mm × 3mm) PLASTIC DFN
50ns/DIV3442 G15 V IN = 2.9V
V OUT = 3.3V AT 500mA
LTC3442
3442f
200µs/DIV
3442 G22
C OUT = 100µF
LOW ESR TANTALUM
INDUCTOR CURRENT 0.5A/DIV
V OUT 50mV/DIV
1ms/DIV
3442 G23
R LIM = 133k C LIM = .001µF
INDUCTOR CURRENT 0.5A/DIV
R LIM PIN 0.5V/DIV V
OUT 2V/DIV
20µs/DIV
3442 G21
C OUT = 100µF
LOW ESR TANTALUM
INDUCTOR CURRENT 0.5A/DIV
V OUT 50mV/DIV
50ns/DIV
3442 G17
SW12V/DIV
SW22V/DIV
V IN = 4.2V
V OUT = 3.3V AT 500mA
50ns/DIV
3442 G16
SW12V/DIV SW22V/DIV
V IN = 3.3V
V OUT = 3.3V AT 500mA
TYPICAL PERFOR A CE CHARACTERISTICS U W
Switch Pins in Buck-Boost Mode
Switch Pins Entering Buck-Boost Mode
Output Ripple at 1A Load
Load Transient Respon in Fixed Frequency Mode, No Load to 1A
Load Transient Respon in Auto Burst Mode Operation, No Load to 1A
Burst Mode Operation
Puld Overload Using Average Input Current Limit
Transition from Burst Mode
南白黄糕粑Operation to Fixed Frequency Mode
1µs/DIV
3442 G18
V OUT
悲伤歌曲
20mV/DIV AC COUPLED
V IN = 4.2V
V IN = 3.3V
V IN = 2.7V 100µs/DIV
3442 G19
V IN = 3.6V V OUT = 3.3V
C OUT = 47µF, X5R CERAMIC
LOAD 0.5A/DIV
V
OUT 100mV/DIV
100µs/DIV
3442 G20
V IN = 3.6V V OUT = 3.3V
C OUT = 47µF, X5R CERAMIC + 100µF LOW ESR TANTALUM
LOAD 0.5A/DIV
V OUT 100mV/DIV
(T A = 25°C unless otherwi specified).
马桶排名
LTC3442
U
U
U
PI FU CTIO S
SHDN/SS (Pin 1): Combined Soft-Start and Shutdown. Applied voltage <0.4V shuts down the IC. Tie
to >1.4V to enable the IC and >2.4V to ensure the error amp is not clamped from soft-start. An RC network from the shut-down command signal to this pin will provide a soft-start function by limiting the ri time of the V C pin.
R T (Pin 2): Programs the Frequency of the Internal Oscil-lator. Place a resistor from this pin to ground. See the Applications Information ction for component value lection.
SGND (Pin 3): Signal Ground for the IC.
SW1 (Pin 4): Switch Pin Where Internal Switches A and B are Connected. Connect inductor from SW1 to SW2. An optional Schottky diode can be connected from SW1 to ground for a moderate efficiency improvement. Minimize trace length to reduce EMI.
PGND (Pin 5, 13): Power Ground for the Internal NMOS Power Switches. The expod pad must be soldered to PCB ground to provide both electrical contact and a good thermal contact to the PCB.
SW2 (Pin 6): Switch Pin Where Internal Switches C and D are Connected. An optional Schottky diode can be con-nected from SW2 to V OUT for a moderate efficiency im-provement. Minimize trace length to reduce EMI.BURST (Pin 7): Ud to t the Automatic Burst Mode Operation Thresho
ld. Place a resistor and capacitor in parallel from this pin to ground. See the Applications Information ction for component value lection. For manual control, ground the pin to force Burst Mode operation, connect to V OUT to force fixed frequency mode. V OUT (Pin 8): Output of the Synchronous Rectifier. A filter capacitor is placed from V OUT to GND. A ceramic bypass capacitor is recommended as clo to the V OUT and GND pins as possible.
V IN (Pin 9): Input Supply Pin. Internal V CC for the IC. A 10µF ceramic capacitor is recommended as clo to V IN and SGND as possible.
R LIM (Pin 10): Sets the Average Input Current Limit Threshold. Place a resistor and capacitor in parallel from this pin to ground. See the Applications Information ction for component value lection.
V C (Pin 11): Error Amp Output. A frequency compensation network is connected from this pin to FB to compensate the loop. During Burst Mode operation, V C is internally connected to a hold circuit.
FB (Pin 12): Feedback Pin. Connect resistor divider tap here. The output voltage can be adjusted from 2.4V to 5.25V. The feedback reference voltage is typically 1.22V.
