LTC4223-2 Linear Technology, LTC4223-2 Datasheet
LTC4223-2
Related parts for LTC4223-2
LTC4223-2 Summary of contents
Page 1
... It also detects card presence and allows independent control of the 12V and auxiliary 3.3V sup- ply outputs. The LTC4223-1 features a latch-off circuit breaker, while the LTC4223-2 provides automatic retry after a fault. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ...
Page 2
... For more information on tape and reel specifi cations, go to: 2 12V 12V AUXOUT ................................................. –0.3V to 10V Operating Temperature Range LTC4223-1C/ LTC4223-2C ....................... 0°C to 70°C LTC4223-1I/ LTC4223-2I ..................... –40°C to 85°C Storage Temperature Range + 0.3V GN Package ....................................... –65°C to 150°C CC DHD Package ..................................... –65°C to 125°C Lead Temperature (Soldering, 10sec) GN Package ...................................................... 300° ...
Page 3
... 12VIN 12VSENSE (V – 12VIN 12VSENSE V Falling 12VOUT V Falling AUXOUT V 12VOUT V AUXOUT V Rising TIMER V Falling TIMER LTC4223-1/LTC4223-2 =12V, unless otherwise specifi ed. (Note 2) 12VIN MIN TYP MAX ● 2.7 6 ● 2.7 6 ● ● 0.8 2 ● 0.4 1 ● 0.6 1 ● 2.3 2.45 2.6 ● ...
Page 4
... LTC4223-1/LTC4223-2 www.DataSheet4U.com ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are T SYMBOL PARAMETER I TIMER Pull-Up Current TMR(UP) I TIMER Pull-Down Current TMR(DN) Open Drain Outputs Output Low Voltage ( ⎯ F ⎯ A ⎯ U ⎯ L ⎯ ⎯ 1 ⎯ 2 ⎯ P ⎯ G ⎯ O ⎯ O ⎯ ⎯ ...
Page 5
... TEMPERATURE (°C) 422312 G04 Active Current Limit Sense Voltage vs Temperature 100 –50 – TEMPERATURE (°C) 422312 G07 LTC4223-1/LTC4223-2 Specifi cations are T = 25° 3.3V 12IMON Gain Ratio vs Temperature 100 –50 – TEMPERATURE (° ...
Page 6
... LTC4223-1/LTC4223-2 www.DataSheet4U.com TYPICAL PERFORMANCE CHARACTERISTICS 3.3V, V =12V, unless otherwise specifi ed. 12VIN AUX Switch On Resistance vs Temperature 0.5 0.4 0.3 0.2 0.1 –50 – TEMPERATURE (°C) Gate Pull-Up Current vs Temperature –11.0 –10.5 –10.0 –9.5 –9.0 –50 – TEMPERATURE (°C) Gate Fast Pull-Down Current vs ...
Page 7
... An internal 100k resistor pulls up this pin. A high-to-low transition will clear faults. LTC4223-1/LTC4223-2 ⎯ A ⎯ U ⎯ X ⎯ P ⎯ G ⎯ O ⎯ O ⎯ D (Pin 11): Auxiliary Supply Power Status Output. Open drain output that is normally pulled high by an internal 10μ ...
Page 8
... LTC4223-1/LTC4223-2 www.DataSheet4U.com FUNCTIONAL DIAGRAM 12V IN 12V SENSE 12ON 200μA TIMER 2μA AUXON GND AUXIN – 10μA CHARGE PUMP 60mV ACL + – + 1mA – DRIVER 50mV ECB + – + – 12V SUPPLY CONTROL 12V FET ON ...
Page 9
... MOSFET with 10μA pull-up. Connecting an external gate capacitor limits the inrush current charging the load ca- pacitor. If the inrush current exceeds its limited current LTC4223-1/LTC4223-2 value, an internal analog current limit (ACL) amplifi er servos the gate to force 60mV across the external sense ...
Page 10
... LTC4223-1/LTC4223-2 www.DataSheet4U.com APPLICATIONS INFORMATION MP ENABLE PWR ENABLE MP GOOD PWR GOOD FAULT INTELLIGENT PLATFORM MANAGEMENT CONTROLLER 3 3.3V 2.2k PRESENCE RESET The typical LTC4223 application Carrier board for Advanced Mezzanine Cards (AMC), delivering 3.3V auxiliary and 12V power to the AMC module. A control- ler on the Carrier board sequences the turn-on of power supplies and manages the fault and power-good reports from the LTC4223 ...
Page 11
... AUXPGOOD 5V/DIV 12PGOOD 5V/DIV 20ms/DIV Figure 2. Normal Power-Up Sequence LTC4223-1/LTC4223-2 Once AUXOUT signals power is good and the TIMER pin and returns to <0.2V, the external MOSFET is then allowed to CC turn on by charging up the GATE with a 10μA current source (Figure 2). The voltage at the GATE pin rises with a slope equal to 10μ ...
Page 12
... The fi lter time is given by C • 6[ms/μF For cooling off during an auto-retry cycle after an overcurrent fault on auxiliary or 12V supply (LTC4223-2). The cool-off time is given by C [ms/μF] after an auxiliary supply fault and C μF] after a 12V supply fault. EN 2V/DIV TIMER ...
Page 13
... C After the MOSFET turns off, the TIMER pin capacitor dis- charges with a 2μA pull-down current. For the auto-retry version (LTC4223-2), if the TIMER discharges to below 0.2V, a new start-up cycle will begin. The TIMER starts ramping up and clears faults when it exceeds 1.235V; ...
Page 14
... F ⎯ A ⎯ U ⎯ L ⎯ cleared by tog- gling the ON pins. Faults are cleared automatically in the LTC4223-2 auto-retry version. If there is signifi cant supply lead inductance, a severe output short may collapse the input to ground before the LTC4223 can bring the current under control. In this case the undervoltage lockout will activate after a 12μ ...
Page 15
... Bringing AUXIN or 12V undervoltage threshold will not reset the fault latches. For the auto-retry version (LTC4223-2), the latched fault will be cleared automatically after a cool-off timing cycle. LTC4223-1/LTC4223-2 Auto-Retry after a Fault (LTC4223-2) At time point 1 in Figure fault latched-off the 3 ...
Page 16
... LTC4223-1/LTC4223-2 www.DataSheet4U.com APPLICATIONS INFORMATION GATE Pin Voltage The gate drive at 12V is compatible with any logic GATE level MOSFET. The guaranteed range of gate drive is 4.5V to 7.9V, with a typical of 6.2V. Active Current Loop Compensation The compensation network consisting of resistor R gate slew rate control capacitor C active current limit circuit ...
Page 17
... Figure 9. Auto-Retry after 12V Overcurrent Fault I LOAD Q1 are fed directly from IN LOAD Figure 10. High Side Current Sense with LTC1197L ADC LTC4223-1/LTC4223-2 START 12V GATE RAMP WHEN STARTUP CONDITIONS ARE MET 12V OUTPUT IN CURRENT LIMIT FAULT PULLS LOW AND RESTART OF RESTART OF COOL-OFF CYCLE DEBOUNCE CYCLE 4 5 ...
Page 18
... LTC4223-1/LTC4223-2 www.DataSheet4U.com APPLICATIONS INFORMATION R2 51Ω AUXIN Figure 11. RC Network for V PCB Layout Considerations For proper operation of the LTC4223’s circuit breaker, Kelvin-connection to the sense resistor is strongly rec- ommended. The PCB layout should be balanced and symmetrical to minimize wiring errors. In addition, the ...
Page 19
... Thermal Impedance plot indicates that the worse-case increase in junction temperature during the short-circuit condition is 13.2°C using Z This will not cause the maximum junction temperature to be exceeded. The SOA curves of the Si7336ADP are also checked to be safe under this condition. LTC4223-1/LTC4223 • ...
Page 20
... LTC4223-1/LTC4223-2 www.DataSheet4U.com TYPICAL APPLICATION BACKPLANE CARD CONNECTOR CONNECTOR 12V SMAJ13A 5V R6 10k SMAJ7.0A PWRFLT PWREN BD_SEL GND 20 Card Resident Application with 5V Auxiliary Supply R S 4mΩ Si7336ADP R1 10Ω 10Ω 100nF 12V 12V IN SENSE AUXIN R2 R7 51Ω 2.7Ω ...
Page 21
... R7 51Ω 2.7Ω 100nF 330nF 12ON 3.3V 3.3V R8 10k R9 R5 LTC4223-1 10k 10k AUXON Q2 12PGOOD 2N7002K FAULT EN TIMER C T 0.1μF LTC4223-1/LTC4223-2 Q1 12V 10A + 15nF G 1000μF 47Ω 12V GATE 12V OUT 3.3V AUXOUT 150mA + C L2 150μF 3.3V R4 10k AUXPGOOD 3.3V 1μ ...
Page 22
... LTC4223-1/LTC4223-2 www.DataSheet4U.com PACKAGE DESCRIPTION .254 MIN .0165 ± .0015 RECOMMENDED SOLDER PAD LAYOUT .007 – .0098 (0.178 – 0.249) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES 2. DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" ...
Page 23
... LTC DWG # 05-08-1707) 0.70 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 4.34 ±0.05 (2 SIDES) 5.00 ±0.10 (2 SIDES 0.20 TYP 4.00 ±0.10 2.44 ± 0.10 (2 SIDES) (2 SIDES) 0.75 ±0.05 0.00 – 0.05 LTC4223-1/LTC4223 0.115 0.40 ± 0.10 TYP 9 16 PIN 1 NOTCH (DHD16) DFN 0504 8 1 0.25 ± 0.05 0.50 BSC 4.34 ±0.10 (2 SIDES) BOTTOM VIEW—EXPOSED PAD 422312f 23 ...
Page 24
... LTC4223-1/LTC4223-2 www.DataSheet4U.com TYPICAL APPLICATION BACKPLANE CARD CONNECTOR CONNECTOR 12V SMAJ13A 3.3V Z2 SMAJ5.0A BD_SEL RELATED PARTS PART NUMBER DESCRIPTION LTC1421 Dual Channel, Hot Swap Controller LTC1645 Dual Channel, Hot Swap Controller LTC1647-1/LTC1647-2/ Dual Channel, Hot Swap Controller LTC1647-3 LTC4210 Single Channel, Hot Swap Controller ...