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Part: LT1619ES8
Category:
Power Management
-> Regulators
-> Switching Regulators
-> Step-Up and Flyback
Description: LT1619, Low Voltage Current Mode PWM Controller
Company: Linear Technology Corporation
Datasheet: Download LT1619ES8 datasheet File size : 550 kB
Request For quote: Find where to buy LT1619ES8
Datasheet text preview:
LT1619 Low Voltage Current Mode PWM Controller
FEATURES
s s s s
DESCRIPTIO
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Wide VIN Range: 1.9V to 18V 300kHz Fixed Frequency Current Mode Control 1A Rail-to-Rail N-Channel MOSFET Driver Low 53mV Current Limit Threshold Voltage Improves Efficiency Implements Boost, SEPIC and Flyback Converters Requiring Low Side Power Transistors Internal Current Sense Amplifier with Leading Edge Blanking Up to 500kHz External Synchronization Burst Mode® Operation for High Efficiency at Light Load 140µA Quiescent Current 15µA Shutdown Current 8-Lead MSOP and SO Packages
The LT ®1619 is a fixed frequency PWM controller for implementing current mode DC/DC converters with minimum external parts. The LT1619 operates with input voltages ranging from 1.9V to 18V and is suitable for a variety of battery-powered and distributed DC/DC converters. The internal rail-to-rail N-channel MOSFET driver operates either from the input in the nonbootstrapped mode or from the output in bootstrapped operation. The driver is designed to drive a low side power transistor in boost, SEPIC, flyback and other topologies. Converter efficiency is improved at heavy loads with a 53mV current sense voltage and at light load with Burst Mode operation. The operating frequency is internally set at 300kHz. The oscillator can also be synchronized externally up to 500kHz. No load quiescent current is 140µA and shutdown current is 15µA. The LT1619 is available in 8-lead MSOP and SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation.
APPLICATIO S
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3.3V to 5V DC/DC Converters Distributed Power Supplies Isolated Power Supplies
TYPICAL APPLICATIO
VIN 3.3V
37.4k 12.4k
1 2 3
S/S FB VC GND
VIN DRV LT1619 GATE SENSE
8 7 6 5 0.1µF
+
EFFICIENCY (%)
C1 22µF 0.1µF
L1 5.6µH 5A VOUT 5V 2.2A
M1 Si9804
D1
75k 220pF 15nF
4
+
COUT 440µF
RSENSE 0.01
1619 F01
C1: PANASONIC EEFCDOK220R COUT: KEMET T495X227K010AS (×2) D1: MBRD835L L1: COILCRAFT DO5022P-562
Figure 1. High Efficiency 3.3V to 5V DC/DC Converter
1619fa
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Efficiency
95 90 85 80 75 70 1 10 100 LOAD CURRENT (mA) 1000
1619 F01a
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1
LT1619
ABSOLUTE
AXI U
RATI GS
Input Voltage (VIN) .. 0.3V to 20V Gate Drive Supply Voltage (DRV) .... 0.3V to 20V Shutdown/Synch Voltage (S/S) ....... 0.3V to 20V Feedback Voltage (FB) .... VIN Compensation Voltage (VC) ..... 3V Gate Drive Output Current (GATE) ...... ±1.5A
PACKAGE/ORDER I FOR ATIO
TOP VIEW S/S FB VC GND 1 2 3 4 8 7 6 5 VIN DRV GATE SENSE
ORDER PART NUMBER LT1619EMS8
S/S 1 FB 2 VC 3
MS8 PACKAGE 8-LEAD PLASTIC MSOP
MS8 PART MARKING LTHC
TJMAX = 125°C, JA = 200°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VDRV = 2.5V, VS/S = VIN, COMP open, VSENSE = 0V unless otherwise noted.
PARAMETER Reference Voltage Reference Line Regulation FB Input Bias Current Error Amplifier Transconductance Error Amplifier Output Source Current Error Amplifier Output Sink Current Error Amplifier Clamp Voltage Undervoltage Lockout Threshold Input Voltage Range Switching Frequency Synchronization Frequency Range Maximum Duty Cycle Current Limit Threshold Burst Mode Operation Current Limit
q q q
CONDITIONS Measured at the FB Pin 1.9V VIN 18V VFB = VREF
q
VFB = 1V, VCOMP = 1V VFB = 1.5V, VCOMP = 1V VFB = 1V
1.9V VIN 18V
2
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W
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(Note 1)
Current Sense Voltage (SENSE) ........ 0.5V to VIN Operating Temperature Range (Note 2) .. 40°C to 85°C Junction Temperature (Note 3) ..... 125°C Storage Temperature Range ........ 65°C to 150°C Lead Temperature (Soldering, 10 sec)......... 300°C
TOP VIEW 8 7 6 5 VIN DRV GATE SENSE
ORDER PART NUMBER LT1619ES8
GND 4
S8 PART MARKING 1619
S8 PACKAGE 8-LEAD PLASTIC SO
TJMAX = 125°C, JA = 120°C/ W
MIN 1.22
TYP 1.24 0.004 10
MAX 1.26 0.05 25 260 14 14 2.2 1.85 18
UNITS V %/V nA µ 1 µA µA V V V kHz kHz % mV mV
80 4 4 1.6 1.65 1.9 220 370 88 40
q
170 8.7 8.7
300 92 53 10
360 500 66
1619fa
LT1619
ELECTRICAL CHARACTERISTICS
The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VDRV = 2.5V, VS/S = VIN, COMP open, VSENSE = 0V unless otherwise noted.
PARAMETER Current Sense Input Current Current Limit Delay Driver Output Rise Time Driver Output Fall Time Driver Output High Level Driver Output Low Level Shutdown Driver Output Level Idle Mode Driver Output Level S/S Pin Current Operating Supply Current Quiescent Supply Current Shutdown Supply Current Shutdown Threshold Shutdown Delay Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired. Note 2: The LT1619E is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. CL = 3300pF CL = 3300pF IOUT = 20mA IOUT = 200mA IOUT = 20mA IOUT = 200mA VS/S = 0V, IOUT = 20mA VS/S = VIN, VFB = 1.5V, IOUT = 20mA VS/S = VIN VS/S = 0V VFB = 1V VS/S = VIN, VFB = 1.5V VS/S = 0V VS/S = 0V, VIN = 18V, TA = 85°C 0.45 12 17
q
CONDITIONS VSENSE = 0V
q
MIN 90
TYP 120 150 30 35
MAX 150
UNITS µA ns ns ns V V
VDRV 0.6 VDRV 1.6
VDRV 0.35 VDRV 1.2 100 0.5 100 100 200 0.7 200 200 4 2 9 140 15 40 220 19 1.2 33
mV V mV mV µA µA mA µA µA µA V µs
Note 3: TJ is calculated from the ambient temperature TA, the power dissipation PD and the thermal resistance JA of the package according to the formula: TJ = TA + PD · JA
TYPICAL PERFOR A CE CHARACTERISTICS
Bandgap Voltage vs Temperature
1.245 1.243 1.241
BANDGAP VOLTAGE (V)
VIN = 2.5V
1.239
IS/S (µA)
1.237 1.235 1.233 1.231
2 1 0 1
TA = 85°C
S/S PIN CURRENT (µA)
1.229 1.227 1.225 40 20 0 20 40 60 80 100 120
1619 G01
TEMPERATURE (°C)
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IS/S vs VS/S
5 TA = 40°C 4 3 TA = 25°C 4 5
S/S Pin Current vs Temperature
VS/S = 2.5V 3 2 1 0 1 2 VS/S = 0V
2 3 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VS/S (V)
1619 G02
3 40 20
0
20 40 60 80 TEMPERATURE (°C)
100 120
1619 G03
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