FEATURES
■ ■ ■ ■ ■ ■ ■ ■
LT3585-0/LT3585-1 LT3585-2/LT3585-3 Photoflash Chargers with Adjustable Input Current and IGBT Drivers DESCRIPTIO
The LT®3585 series are highly integrated ICs designed to charge photoflash capacitors in digital and film cameras. A new control technique allows for the use of extremely small transformers. Each part contains an on-chip high voltage NPN power switch. Output voltage detection is completely contained within the part, eliminating the need for any discrete zener diodes or resistors. The output voltage can be adjusted by simply changing the turns ratio of the transformer. The CHRG/IADJ pin gives full control of the part to the user. Driving CHRG/IADJ low puts the part in low power shutdown. The CHRG/IADJ pin can also be used to reduce the input current of the charger, useful in extending battery life. The DONE pin indicates when the part has completed charging. The LT3585 series of parts are housed in tiny 3mm × 2mm DFN packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Adjustable Input Current Integrated IGBT Driver No Output Voltage Divider Needed Uses Small Transformers: 5.8mm × 5.8mm × 3mm Fast Photoflash Charge Times Charges Any Size Photoflash Capacitor Supports Operation from Single Li-Ion Cell, Two AA Cells or any Supply from 1.5V Up to 16V Small 10-Lead (3mm × 2mm) DFN Package
REDUCED MODE CHARGE TIME (Sec) 6.6 9.2 12.6 14.6
Fast Charge Time
NORMAL MODE INPUT CHARGE TIME VERSION CURRENT (mA) (Sec) LT3585-3 800/400 3.3 LT3585-0 550/275 4.6 LT3585-2 400/200 5.8 LT3585-1* 250/115 5.0 100µF capacitor, 320V, VIN = VBAT = 3.6V *50µF capacitor, 320V, VIN = VBAT = 3.6V
APPLICATIO S
■ ■ ■
Digital/Film Camera Flash PDA/Cell Phone Flash Emergency Strobe
TYPICAL APPLICATIO
LT3585-1 Photoflash Charger Uses High Efficiency 2mm Tall Transformers with Tunable IGBT Gate Drive
DANGER HIGH VOLTAGE! OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY VBAT 2 AA OR 1 TO 2 Li-Ion
1:10:2 4.7µF 1
320V 4 1M
•
2 VBAT DONE VIN 5V CHRG/IADJ LT3585-1 VIN 0.22µF IGBTPWR IGBTIN IGBTPU IGBTPD SW GND
•5
+
50µF PHOTOFLASH CAPACITOR
2.2µF 600V TRIGGER T 1 3 2
A
VOUT 50V/DIV
FLASHLAMP
C
IIN 500mA/DIV
TO GATE OF IGBT 20Ω TO 160Ω
3585 TA01a
U
U
U
LT3585-1 Charging Waveform Normal Input Current Mode
VBAT = 3.6V COUT = 50µF
1sec/DIV
3585 TA01b
3585f
1
LT3585-0/LT3585-1 LT3585-2/LT3585-3 ABSOLUTE
(Note 1)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW IGBTIN 1 IGBTPWR 2 GND 3 VIN 4 VBAT 5 11 10 IGBTPU 9 8 7 6 IGBTPD SW CHRG/IADJ DONE
VIN Voltage ................................................................16V VBATT Voltage ............................................................16V SW Voltage ...............................................................60V SW Pin Negative Current...........................................–1A CHRG/IADJ Voltage...................................................10V IGBTPWR Voltage .....................................................10V IGBTIN Voltage .........................................................10V IGBTPU Voltage ........................................................10V IGBTPD Voltage ........................................................10V DONE Voltage ...........................................................10V Current Into DONE Pin ............................... 0.2mA/–1mA Maximum Junction Temperature .......................... 125°C Operating Temperature Range (Note 2) ... –40°C to 85°C Storage Temperature Range................... –65°C to 125°C
DDB PACKAGE 10-LEAD (3mm × 2mm) PLASTIC DFN TJMAX = 125°C, θJA = 76°C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER LT3585EDDB-0 LT3585EDDB-1 LT3585EDDB-2 LT3585EDDB-3
DDB PART MARKING LCLK LCLJ LCLH LCFX
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
PARAMETER Quiescent Current VIN Voltage Range VBAT Voltage Range Switch Current Limit
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VBAT = VCHRG = 3V unless otherwise noted (Note 2). Specifications are for the LT3585-0, LT3585-1, LT3585-2, LT3585-3 unless otherwise noted.
CONDITIONS VCHRG = 3V, Not Switching VCHRG = 0V, In Shutdown
● ●
MIN
TYP 5 0
MAX 8 1 16 16
UNITS mA µA V V A A A A mV mV mV mV
2.5 1.5 1.55 1.1 0.75 0.45 1.7 1.2 0.85 0.55 485 330 230 140
LT3585-3 (Note 3) LT3585-0 (Note 3) LT3585-2 (Note 3) LT3585-1 (Note 3) LT3585-3, ISW = 1.4A LT3585-0, ISW = 1A LT3585-2, ISW = 700mA LT3585-1, ISW = 400mA Measured as VSW – VBAT 300ns Pulse Width Measured as VSW – VBAT VCHRG = 3V VCHRG = 0V VBAT = VSW = 5V, In Shutdown
● ● ●
1.85 1.3 0.95 0.65
Switch VCESAT
VOUT Comparator Trip Voltage VOUT Comparator Overdrive DCM Comparator Trip Voltage CHRG/IADJ Pin Current Switch Leakage Current CHRG/IADJ Minimum Enable Voltage
31 30.5 80
31.5 31.5 200 130 45 0 0.01
32 32.5 400 180 70 0.1 1
1.1
2
U
V V mV mV µA µA µA V
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W
U
U
WW
W
LT3585-0/LT3585-1 LT3585-2/LT3585-3 ELECTRICAL CHARACTERISTICS
PARAMETER CHRG/IADJ Three-State Voltage for Reduced Input Current CHRG/IADJ Voltage Range for Normal Input Current CHRG/IADJ Low Voltage Delay Time for Reduced Input Current Mode CHRG/IADJ Pin Three Stated: VBAT = 4.2V, Fresh Li-Ion Cell VBAT = 2.8V, Dead Li-Ion Cell VBAT = 3V, Fresh 2 AA Cells VBAT = 2V, Dead 2 AA Cells High→Low→High 100kΩ from VIN to DONE 33µA into DONE Pin VDONE = 3V, DONE NPN Off
● ● ●
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VBAT = VCHRG = 3V unless otherwise noted (Note 2). Specifications are for the LT3585-0, LT3585-1, LT3585-2, LT3585-3 unless otherwise noted.
CONDITIONS CHRG/IADJ > 1.1V then Float
● ●
MIN 1.1 1.6
TYP 1.28
MAX 1.4 10 0.3
UNITS V V V µs µs µs µs µs V
5.2 7.2 6.8 9.5 20 3 120 1 2.5 1.5 0.5 0.4 0.13 200 100 10
Minimum CHRG/IADJ Pin Low Time DONE Output Signal High DONE Output Signal Low DONE Leakage Current IGBTPWR Voltage Range IGBT Input High Level IGBT Input Low Level IGBT Output Rise Time IGBT Output Fall Time
mV nA V V V µs µs
IGBTPU Pin, COUT = 4000pF, IGBTPWR = 5V, IGBTIN = 0V→1.5V, 10%→90% IGBTPD Pin, COUT = 4000pF, IGBTPWR = 5V, IGBTIN = 1.5V→0V, 90%→10%
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Ratings are for DC levels only.
Note 2: The LT3585 series is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Current limit is guaranteed by design and/or correlation to static test.
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3
LT3585-0/LT3585-1 LT3585-2/LT3585-3 TYPICAL PERFOR A CE CHARACTERISTICS
LT3585-0 Charging Waveform Normal Input Current Mode LT3585-0 curves use Figure 11, LT3585-1 curves use Figure 12, LT3585-2 curves use Figure 13 and LT3585-3 curves use Figure 14 unless otherwise noted. LT3585-1 Charging Waveform Normal Input Current Mode LT3585-2 Charging Waveform Normal Input Current Mode
VOUT 50V/DIV
AVERAGE INPUT CURRENT 1A/DIV VBAT = 3.6V COUT = 50µF
0.5s/DIV
LT3585-3 Charging Waveform Normal Input Current Mode
VOUT 50V/DIV
AVERAGE INPUT CURRENT 1A/DIV VBAT = 3.6V COUT = 50µF
0.5s/DIV
LT3585-2 Charging Waveform Reduced Input Current Mode
CHARGE TIME (SECONDS)
VOUT 50V/DIV
AVERAGE INPUT CURRENT 1A/DIV VBAT = 3.6V COUT = 50mF
1s/DIV
4
UW
VOUT 50V/DIV
VOUT 50V/DIV
3585 G01
AVERAGE INPUT CURRENT 500mA/DIV VBAT = 3.6V COUT = 50µF
2s/DIV
3585 G02
AVERAGE INPUT CURRENT 1A/DIV VBAT = 3.6V COUT = 50µF
1s/DIV
3585 G03
LT3585-0 Charging Waveform Reduced Input Current Mode
LT3585-1 Charging Waveform Reduced Input Current Mode
VOUT 50V/DIV
VOUT 50V/DIV
3585 G04
AVERAGE INPUT CURRENT 1A/DIV VBAT = 3.6V COUT = 50µF
0.5s/DIV
3585 G05
AVERAGE INPUT CURRENT 500mA/DIV VBAT = 3.6V COUT = 50µF
2s/DIV
3585 G06
LT3585-3 Charging Waveform Reduced Input Current Mode
8 7 6 5 4 3 2 1 0
Charge Time* Normal Input Current Mode
LT3585-0 LT3585-1 LT3585-2 LT3585-3
VOUT 50V/DIV
3585 G07
AVERAGE INPUT CURRENT 1A/DIV VBAT = 3.6V COUT = 50µF
0.5s/DIV
3585 G08
2
3
4
5
6 VBAT (V)
7
8
9
10
3585 G09
*USING RUBYCON 330V, 50µF PHOTOFLASH OUTPUT CAPACITOR (FW SERIES)
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LT3585-0/LT3585-1 LT3585-2/LT3585-3 TYPICAL PERFOR A CE CHARACTERISTICS
Charge Time* Reduced Input Current Mode
25 700 LT3585-0 LT3585-1 LT3585-2 LT3585-3 600 INPUT CURRENT (mA) 500 400 300 200 100 0 2 3 4 5 6 7 8 9 10 0 100 VOUT (V)
3585 G11
LT3585-0 curves use Figure 11, LT3585-1 curves use Figure 12, LT3585-2 curves use Figure 13 and LT3585-3 curves use Figure 14 unless otherwise noted. LT3585-0 Input Current Normal Input Current Mode
300 250 INPUT CURRENT (mA) 200 150 100 50 0 200 300 0 100 VOUT (V)
3585 G12
CHARGE TIME (SECONDS)
20 15
10
5
0
3585 G10 VBAT (V) *USING RUBYCON 330V, 50µF PHOTOFLASH OUTPUT CAPACITOR (FW SERIES)
LT3585-2 Input Current Normal Input Current Mode
450 400 350 INPUT CURRENT (mA) INPUT CURRENT (mA) 300 250 200 150 100 50 0 0 100 VOUT (V)
3585 G13
INPUT CURRENT (mA)
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 200 300
LT3585-1 Input Current Reduced Input Current Mode
120 100 INPUT CURRENT (mA) INPUT CURRENT (mA) 80 60 40 20 0 0 100 VOUT (V)
3585 G16
INPUT CURRENT (mA)
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 200 300
UW
LT3585-1 Input Current Normal Input Current Mode
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 200 300
LT3585-3 Input Current Normal Input Current Mode
900 800 700 600 500 400 300 200 100 0 0 100 VOUT (V)
3585 G14
LT3585-0 Input Current Reduced Input Current Mode
350 300 250 200 150 100 50 0 0 100 VOUT (V)
3585 G15
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 200 300
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 200 300
LT3585-2 Input Current Reduced Input Current Mode
250 500 450 200 400 350 300 250 200 150 100 50 0
LT3585-3 Input Current Reduced Input Current Mode
150
100
50
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 0 100 VOUT (V)
3585 G17
0 200 300
VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 0 100 VOUT (V)
3585 G18
200
300
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LT3585-0/LT3585-1 LT3585-2/LT3585-3 TYPICAL PERFOR A CE CHARACTERISTICS
LT3585-0 Efficiency Normal Input Current Mode
90 USING KIJIMA SBL-5.6-1 TRANSFORMER 90 USING KIJIMA SBL-5.6S-1 TRANSFORMER
LT3585-0 curves use Figure 11, LT3585-1 curves use Figure 12, LT3585-2 curves use Figure 13 and LT3585-3 curves use Figure 14 unless otherwise noted. LT3585-1 Efficiency Normal Input Current Mode
90 USING KIJIMA SBL-5.6-1 TRANSFORMER
80 EFFICIENCY (%) EFFICIENCY (%)
70
70
EFFICIENCY (%)
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G19
LT3585-3 Efficiency Normal Input Current Mode
90 USING TDK LDT565630T-041 TRANSFORMER 80 EFFICIENCY (%) EFFICIENCY (%) 80 90
EFFICIENCY (%)
70
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G22
LT3585-2 Efficiency Reduced Input Current Mode
90 USING KIJIMA SBL-5.6-1 TRANSFORMER 90
80 EFFICIENCY (%) EFFICIENCY (%)
70
VOUT (V)
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G25
6
UW
LT3585-2 Efficiency Normal Input Current Mode
80
80
70
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G19
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G21
LT3585-0 Efficiency Reduced Input Current Mode
90 USING KIJIMA SBL-5.6-1 TRANSFORMER
LT3585-1 Efficiency Reduced Input Current Mode
USING KIJIMA SBL-5.6S-1 TRANSFORMER
80
70
70
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G23
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G24
LT3585-3 Efficiency Reduced Input Current Mode
330 USING TDK LDT565630T-041 TRANSFORMER 328
LT3585-0 Output Voltage
80
70
326
60 VBAT = 4.2V VBAT = 3.6V VBAT = 2.5V 50 50 100 150 200 VOUT (V) 250 300
3585 G26
324 TA = –40°C TA = 25°C TA = 85°C 2 3 4 5 VBAT (V) 6 7 8
3585 G27
322
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LT3585-0/LT3585-1 LT3585-2/LT3585-3 TYPICAL PERFOR A CE CHARACTERISTICS
LT3585-1 Output Voltage
322 320 318 VOUT (V) VOUT (V) 316 314 312 310 TA = –40°C TA = 25°C TA = 85°C 326 324 322 330 318 316 314 TA = –40°C TA = 25°C TA = 85°C VOUT (V) 326
LT3585-0 curves use Figure 11, LT3585-1 curves use Figure 12, LT3585-2 curves use Figure 13 and LT3585-3 curves use Figure 14 unless otherwise noted. LT3585-2 Output Voltage
330
2
3
4
5 VBAT (V)
6
LT3585-0 Switch Waveform Normal Input Current Mode
VSW 10V/DIV IPRI 1A/DIV
VBAT = 3.6V VOUT = 100V
2µs/DIV
LT3585-0 Switch Waveform Reduced Input Current Mode
1.8
CURRENT LIMIT (A)
LT3585-0 1.2 0.9 0.6 0.3 0 –50 –30 –10 10 20 30 40 60 TEMPERATURE (°C) *DYNAMIC CURRENT LIMIT IS HIGHER THAN DC CURRENT LIMIT LT3585-2
SWITCH CURRENT (mA)
VSW 10V/DIV
IPRI 1A/DIV
VBAT = 3.6V VOUT = 300V
2µs/DIV
UW
7 8
3585 G28 3585 G31 3585 G34
LT3585-3 Output Voltage
TA = –40°C TA = 25°C TA = 85°C
328
324
322
2
3
4
5 VBAT (V)
6
7
8
3585 G29
320
2
3
4
5 VBAT (V)
6
7
8
3585 G30
LT3585-0 Switch Waveform Reduced Input Current Mode
LT3585-0 Switch Waveform Normal Input Current Mode
VSW 10V/DIV IPRI 1A/DIV
VSW 10V/DIV
IPRI 1A/DIV
VBAT = 3.6V VOUT = 100V
2µs/DIV
3585 G32
VBAT = 3.6V VOUT = 300V
2µs/DIV
3585 G33
Switch DC Current Limit*
10 LT3585-3 1.5 9 8 7 6 5 4 3 2 1 80
3585 G35
LT3585-0/LT3585-1/LT3585-2/ LT3585-3 Switch Breakdown Voltage
SW PIN IS RESISTIVE UNTIL BREAKDOWN VOLTAGE DUE TO INTEGRATED RESISTORS. THIS DOES NOT INCREASE QUIESCENT CURRENT OF THE PART TA = –40°C TA = 25°C TA = 85°C
LT3585-1
0
0
10 20 30 40 50 60 70 80 90 100 SWITCH VOLTAGE (V)
3585 G36
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LT3585-0/LT3585-1 LT3585-2/LT3585-3 PI FU CTIO S
IGBTIN (Pin 1): Logic Input for the IGBT Driver. When this pin is driven higher than 1.5V, the output goes high. When the pin is below 0.5V, the output will go low. IGBTPWR (Pin 2): Supply Pin for the IGBT Driver. Must be locally bypassed with a good quality ceramic capacitor. The minimum operating voltage for the IGBT driver is 2.5V. GND (Pin 3): Ground. Tie directly to local ground plane. VIN (Pin 4): Input Supply Pin. Must be locally bypassed with a good quality ceramic capacitor. The minimum operating voltage for VIN is 2.5V. VBAT (Pin 5): Battery Supply Pin. Must be locally bypassed with a good quality ceramic capacitor. The minimum operating voltage for VBAT is 1.5V. DONE (Pin 6): Open NPN Collector Indication Pin. When target output voltage is reached, NPN turns on. This pin needs a proper pull-up resistor or current source. CHRG/IADJ (Pin 7): Charge and Input Current Adjust Pin. A low (1.1V) transition on this pin puts the part into power delivery mode. Once the target output voltage is reached, the part will stop charging the output. Toggle this pin to start charging again. Ground to shut down. To enter into the input current reduction mode, the voltage on this pin should be driven high ( >1.1V ) and then floated. (For more information refer to the Operation section of this data sheet.) To enter normal mode, the voltage should be driven higher than 1.6V. SW (Pin 8): Switch Pin. This is the collector of the internal NPN Power switch. Minimize the metal trace area connected to this pin to minimize EMI. Tie one side of the primary of the transformer to this pin. The target output voltage is set by the turns ratio of the transformer. Choose turns ratio N by the following equation: N= VOUT + 2 31.5
8
U
U
U
where VOUT is the desired output voltage. IGBTPD (Pin 9): Pull-down Output for IGBT Gate. Connect this pin to the IGBT Gate. Add a series resistor to increase the turn-off time to protect the IGBT. IGBTPU (Pin 10): Pull-up Output for IGBT Gate. Connect this pin to the gate of the IGBT. Exposed Pad (Pin 11): Ground. Tie directly to local ground plane.
3585f
LT3585-0/LT3585-1 LT3585-2/LT3585-3 SI PLIFIED BLOCK DIAGRA
TO BATTERY C1 VIN C2 4 DONE CHIP POWER VIN 2.5V MAX 1.5V MAX 5 VBAT R2 60k DCM COMPARATOR 8 PRIMARY
•
6
SW
A5 UVLO
A4 A3
SECONDARY
Q3 MASTER LATCH Q S Q1 ENABLE UVLO
Q2
Q R
R1 2.5k
+
A2 VOUT COMPARATOR
VARIABLE DELAY DRIVER S R SWITCH Q LATCH RESET DOMINANT A1
–
1.25V REFERENCE
CHRG/IADJ 7 ONE SHOT
2
IGBTPWR
1
IGBTIN
IGBT DRIVE CIRCUITRY
Figure 1
–
+
W
D1 T1
–
+
+
–
W
•
VOUT
+
COUT
+ –
130mV
Q1
+
20mV RM GND 3
–
+–
IGBTPU IGBTPD
10 9
3585 F01
LT3585-3, RM = 12mΩ LT3585-0, RM = 17mΩ LT3585-2, RM = 24mΩ LT3585-1, RM = 36mΩ
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LT3585-0/LT3585-1 LT3585-2/LT3585-3 OPERATIO
The LT3585 series of parts operate on the edge of discontinuous conduction mode. When CHRG/IADJ is driven higher than 1.1V, the master latch is set. This enables the part to deliver power to the photoflash capacitor. When the power switch, Q1, is turned on, current builds up in the primary of the transformer. When the desired current level is reached, the output of comparator A1 goes high, resetting the switch latch that controls the state of Q1, and the output of the DCM comparator goes low. Q1 now turns off and the flyback waveform on the SW node quickly rises to a level proportional to VOUT. The secondary current flows through high voltage diode(s), D1, and into the photoflash capacitor. When the secondary current decays to zero, the voltage on the SW node collapses. When this voltage reaches 130mV higher than VBAT, the output of A3 goes high. This sets the switch latch and the power switch, Q1, turns back on. This cycle repeats until the target VOUT level is reached. When the target VOUT is reached, the master latch resets and the DONE pin goes low. The input current of an LT3585 series circuit can be reduced by changing the voltage of the CHRG/IADJ pin. When this pin is between 1.1V and 1.4V, a time delay is
Normal Operation
CHRG/IADJ ≥ 1.6V IPRI
VSW VOUT 100V/DIV
IPRI CHRG/IADJ 2V/DIV TIME Extra Delay Added (~5.2µs at VBAT = 4.2V) VSW LT3585-1 VBAT = 3.6V COUT = 50µF THREE STATE* 1sec/DIV CHRG/IADJ PIN STATE 3V 1.6 500 >0.8 500 >1.0 500 >2 2 • IPK 2 • LPRI ILK • VBAT
VIN
TO DONE
where ILK is the known leakage current, IPK is the transformer peak primary current, and LPRI is the transformer primary inductance. If this condition is not met, a runaway condition could occur. The LT3585 series part would continue to charge the output voltage past the internal output trip voltage. Figure 17 shows the AC ripple of a typical auto-refresh circuit with the proper selection of RT and CT.
VOUT 2V/DIV AC RIPPLE
CHRG/IADJ 2V/DIV
Figure 17. VOUT AC Ripple in Auto Refresh Mode
AUTO REFRESH
3585f
LT3585-0/LT3585-1 LT3585-2/LT3585-3 PACKAGE DESCRIPTIO U
DDB Package 10-Lead Plastic DFN (3mm × 2mm)
(Reference LTC DWG # 05-08-1722 Rev Ø)
0.64 ± 0.05 (2 SIDES) 0.70 ± 0.05 2.55 ± 0.05 1.15 ± 0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 2.39 ± 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS R = 0.115 TYP 6 3.00 ± 0.10 (2 SIDES) R = 0.05 TYP 0.40 ± 0.10 10 2.00 ± 0.10 (2 SIDES) 0.64 ± 0.05 (2 SIDES) 5 0.25 ± 0.05 2.39 ± 0.05 (2 SIDES) BOTTOM VIEW—EXPOSED PAD 1 PIN 1 R = 0.20 OR 0.25 × 45° CHAMFER
(DDB10) DFN 0905 REV Ø
PIN 1 BAR TOP MARK (SEE NOTE 6)
0.200 REF
0.75 ± 0.05
0.50 BSC
0 – 0.05
NOTE: 1. DRAWING CONFORMS TO VERSION (WECD-1) IN JEDEC PACKAGE OUTLINE M0-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
3585f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
19
LT3585-0/LT3585-1 LT3585-2/LT3585-3 TYPICAL APPLICATIO U
T1 1:10.3 C1 4.7µF D1 320V
VBAT 1.5V TO 8V
• •
+
COUT PHOTOFLASH CAPACITOR
R1 100k DONE CHARGE VIN 2.5V TO 8V
VBAT DONE
SW GND
C2 0.22µF
CHRG/IADJ LT3585-3 VIN IGBTPWR IGBTIN IGBTPU IGBTPD R2 20Ω TO 160Ω TO GATE OF IGBT
3585 F18
C1: 4.7µF, 10V, X5R OR X7R C2: 0.22µF, 10V, X5R OR X7R COUT: RUBYCON 330V, 50µF PHOTOFLASH OUTPUT CAPACITOR (FW SERIES) D1: VISHAY GSD2004S DUAL DIODE CONNECTED IN SERIES R1: PULL-UP RESISTOR NEEDED IF DONE PIN USED T1: TOKYO COIL TTRN-0530-022-T, LPRI = 4µH, N = 10.3
Figure 18. LT3585-3 Typical Application
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