LTC4222 Linear Technology, LTC4222 Datasheet
LTC4222
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LTC4222 Summary of contents
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... The device features adjustable, analog, foldback current limit circuits and a Soft-Start circuit that sets the dI/dt of the inrush currents part to latch off or automatically restart after the LTC4222 detects a fault on either channel. The controller has additional features to interrupt the host when a fault has occurred, notify when output power is ...
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... ALERT, SCL, SDA, SDAI, SDAO ............ –0.3V to 6.5V Output Voltages GATEn, GPIOn ........................................ –0.3V to 35V – 6. 0.3V Operating Temperature Range DDn + n + 0.3V LTC4222C ................................................ 0°C to 70°C LTC4222I.............................................. –40°C to 85° 0.3V Storage Temperature Range ................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) + 0.3V SSOP ................................................................ 300°C CC ...
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... CONFIG, EN, ON Hysteresis ΔV CONFIG,EN,ON(HYST) ΔV FB Power Good Hysteresis FB(HYST) PART MARKING* PACKAGE DESCRIPTION LTC4222CG 36-Lead Plastic SSOP LTC4222IG 36-Lead Plastic SSOP 32-Lead (5mm × 5mm) Plastic QFN LTC4222 32-Lead (5mm × 5mm) Plastic QFN LTC4222 http://www.linear.com/leadfree/ http://www.linear.com/tapeandreel/ l The denotes the specifi ...
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... LTC4222 www.DataSheet4U.com ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER ΔV OV Hysteresis OV(HYST) ΔV UV Hysteresis UV(HYST) I CONFIG, FB, ON, OV and UV Input Current (IN) EN Pull-Up Current I EN(UP Reset Threshold Voltage UV(RTH) ΔV UV Reset Threshold Hysteresis UV(RHYST) V GPIO Input Threshold ...
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... Maximum specifi cations are limited by the LSB step size and the single shot measurement. Typical specifi cations are measured from 1/4, 1/2, 3/4 areas of the quantization band. Note 5: Guaranteed by design and not subject to test. LTC4222 MIN TYP MAX ...
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... LTC4222 www.DataSheet4U.com TYPICAL PERFORMANCE CHARACTERISTICS DD1 DD1 1.0 0.9 0.8 0.7 0.6 0.5 0 (V) DD1 INTV LOAD 3.50 3.25 V DD2 V DD2 V DD2 3.00 V DD2 2.75 2.50 0 2.5 5.0 7.5 10.0 12.5 I (mA) LOAD DD2 DD2 4.0 3.5 3.0 2.5 2 (V) DD2 4222 G01 V vs Temperature TH(UV) 1.250 1.245 1.240 = 2. 1.235 = 12V 1.230 1 ...
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... V (V) FB 4222 G07 Δ GATE GATE 6.5 6.0 5.5 5.0 = 2.9V 4 12V 4.0 100 (A) GATE 4222 G10 LTC4222 T = 25° 12V unless otherwise noted. A DDn V Circuit Breaker vs TH Temperature 1.2 1.4 –50 – TEMPERATURE (°C) 4222 G08 I vs Temperature GATE 12 2.9V DD2 ...
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... LTC4222 www.DataSheet4U.com TYPICAL PERFORMANCE CHARACTERISTICS OL(GPIO) GPIO 0.6 0.5 0.4 0.3 0.2 0 (mA) GPIO ADC DNL vs CODE (ADIN1) 0.5 0.4 0.3 0.2 0.1 0 –0.1 –0.2 –0.3 –0.4 –0.5 256 512 0 768 CODE 8 ADC Total Unadjusted Error vs CODE (ADIN1) 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0 256 512 CODE 4222 G13 ADC Full-Scale Error vs ...
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... CONTROL register bits 6 and 7. Also a power bad fault is logged when the FB pin is low, the LTC4222 has fi nished the startup cycle and the GATE pin is high. See Applications Information. The startup current limit folds back from 50mV sense voltage to 16.6mV as the FB voltage drops from 0.8V to 0.2V. Foldback is not confi ...
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... LTC4222 www.DataSheet4U.com SCL: Serial Bus Clock Input. Data at the SDA pin is shifted in or out on rising edges of SCL. This is a high impedance pin that is generally driven by an open collector output from a master controller. An external pull-up resistor or current source is required. SDAO: (SSOP Package) Serial Bus Data Output. Open- drain output for sending data back to the master control- ler or acknowledging a write operation ...
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... DIDT 0.6V + UVS UV – FAULT + + OVS OV1 – 1.235V – + UVLO1 V UVLO DD – + 0.2V – + – 1.235V 5 10 BIT A/D CONVERTER LTC4222 – + SENSE SENSE (SSOP) + CHARGE – PUMP 0mV TO CB AND CS 50mV 150mV GATE – – – + DRIVER FET PWRGD PG – ...
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... INTV crosses this rising threshold. The CONFIG pin is used to select the desired startup be- havior of the LTC4222. When the CONFIG pin is low, both channels will start up and turn off simultaneously and a fault on either channel will result in both channels turning off, or prevent both channels from starting up ...
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... Several conditions must be present before the external MOSFET for a given channel turns on. First the external Included in the LTC4222 is a 10-bit A/D signal. The 6-input multiplexer ahead of the A/D converter allows to select between the two ADIN pins, the two SOURCE pins and the two current sense devices ...
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... FDD3706 Z1 R11 SA14A R5-1 140k 10Ω R21 0.1μF 4.53k – UV1 V SENSE1 GATE1 DD1 R31 OV1 13.7k ON SDA SCL ALERT CONFIG ADR0 LTC4222 NC ADR1 ADR2 INTV CC C3 0.1μF GND R32 OV2 13.7k – UV2 V SENSE2 GATE2 DD2 R22 3.32k C F2 R5-2 0.1μF R12 10Ω 23.7k ...
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... GATE pin is pulled down with a 450mA current to the SOURCE pin. Overcurrent Fault The LTC4222 has different current limiting behavior during start-up, when the output supply ramps up under TIMER, SS and FB control, and normal operation. As such it can generate an overcurrent fault during both phases of op- eration. Both set the faulting supply’ ...
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... The 20μs fi lter delay and the higher current limit threshold prevent unnecessary resets of the board due to minor current surges. The LTC4222 will stay in the latched off state unless the overcurrent auto-retry bit (CONTROL register bit 2) is set, in which ...
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... If a channel shuts down due to a fault, it may be desirable to restart that channel simply by removing and reinserting the related load card. In cases where the LTC4222 and the switch reside on a backplane or midplane and the load resides on a plug-in card, the EN pin detects when the plug-in card is removed ...
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... Subsequently, when STATUS register bits 0 and 1 are cleared by removal of the fault condition, the switch is allowed to turn on again. The LTC4222 will set FAULT bit 2 and turn off in the event of an overcurrent fault, preventing it from remaining in an overcurrent condition. ...
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... GS Supply Transient Protection The LTC4222 is safe from damage with supply voltages up to 35V. However, spikes above 35V may damage the part. During a short-circuit condition, large changes in current fl owing through power supply traces may cause induc- tive voltage spikes which exceed 35V ...
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... LTC4222 www.DataSheet4U.com APPLICATIONS INFORMATION Selection of the sense resistor, R threshold of 50mV Ω MAX The MOSFET is sized to handle the power dissipation dur- ing inrush when output capacitor C A method to determine power dissipation during inrush is based on the principle that: Energy Energy in Q1 ...
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... Mass write can be disabled by setting 4222 F05 register bit 4 in the CONTROL register of channel 2 to zero. Address (0001 100) is the SMBus Alert Response Address. If the LTC4222 is pulling low on the ALERT pin due to an LTC4222 2 C Bus and SMBus, an 4222f ...
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... Register Address pointer. The master then sends a repeated START condition followed by the S ADDRESS A DATA b7:b0 0 Figure 8. LTC4222 Serial Bus SDA Write Word Protocol A: ACKNOWLEDGE (LOW) A: NOT ACKNOWLEDGE (HIGH) R: READ BIT (HIGH) W: WRITE BIT (LOW) S ADDRESS S: START CONDITION P: STOP CONDITION 4222 F07 Figure 9 ...
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... ADDRESS a7: b7:b0 0 a7:a0 Figure 10. LTC4222 Serial Bus SDA Read Word Protocol ALERT DEVICE S RESPONSE R A ADDRESS ADDRESS a7:a0 Figure 11. LTC4222 Serial Bus SDA Alert Response Protocol LTC4222 DATA A DATA 1 0 b7:b0 0 b7:b0 1 4222 F10 4222 F11 4222f 23 ...
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... LTC4222 APPLICATIONS INFORMATION 2 Table 1. LTC4222 I C Device Addressing DEVICE DESCRIPTION ADDRESS h Mass Write C6 Alert Response ...
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... APPLICATIONS INFORMATION Table 2. LTC4222 Register Addresses and Contents REGISTER ADDRESS Decimal Hex 208 D0h 209 D1h 210 D2h 211 D3h 212 D4h 213 D5h 214 D6h 215 D7h 216 D8h 217 D9h 218 DAh 219 DBh 220 DCh 221 DDh ...
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... LTC4222 www.DataSheet4U.com APPLICATIONS INFORMATION Table 3. CONTROL Registers A – Read/Write BIT CONTROL 1 (D0h) 7:6 GPIO1 Confi gure 5 GPIO1 Output 4 Reserved 3 Channel 1 FET On Control 2 Channel 1 Overcurrent Auto-Retry 1 Channel 1 Undervoltage Auto-Retry Channel 2 Undervoltage Auto-Retry Undervoltage Auto-retry 0 Channel 1 Overvoltage Auto-Retry Table 4. ALERT Registers B – Read/Write ...
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... Overcurrent Fault Occurred Overcurrent Faults Channel 2 Undervoltage Fault Indicates Input Undervoltage Fault Occurred When UV Went Low Occurred was Low was High Channel 2 Overvoltage Fault Indicates Input Overvoltage Fault Occurred When OV Went High Occurred was High was Low LTC4222 4222f 27 ...
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... LTC4222 www.DataSheet4U.com APPLICATIONS INFORMATION Table 7. ADC Register Data Format: ADINn, SOURCEn, SENSEn MSB Bytes – Read/Write* BIT (7) BIT (6) Data (9) Data (8) *Set bit ADC _CONTROL(0) before writing Table 8. ADC Register Data Format: ADINn, SOURCEn, SENSEn LSB Bytes – Read/Write* BIT (7) BIT (6) Data (1) ...
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... C1-1 22nF – UV1 V SENSE1 GATE1 SOURCE1 DD1 OV1 FB1 SDA1 GPIO1 EN1 SDA0 SCL ADIN1 ALERT TIMER INTV CONFIG ON2 ADR0 LTC4222 ON1 ADR1 SS ADR2 INTV ADIN2 68nF EN2 GND GPIO2 OV2 FB2 – UV2 V SENSE2 GATE2 SOURCE2 DD2 R6-2 ...
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... LTC4222 www.DataSheet4U.com PACKAGE DESCRIPTION 5.50 ±0.05 3.45 ± 0.05 4.10 ±0.05 3.50 REF (4 SIDES) 3.45 ± 0.05 RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 30 UH Package 32-Lead Plastic QFN (5mm × 5mm) (Reference LTC DWG # 05-08-1693) 5.00 ± 0.10 (4 SIDES) 0.70 ±0.05 PIN 1 TOP MARK (NOTE 6) PACKAGE 0.25 ± ...
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... BSC 5.00 – 5.60** (.197 – .221) 0° – 8° 0.65 0.55 – 0.95 (.0256) (.022 – .037) BSC 0.22 – 0.38 (.009 – .015) TYP MILLIMETERS (INCHES) LTC4222 12.50 – 13.10* (.492 – .516 7.40 – 8.20 (.291 – .323) ...
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... UV1 V SENSE1 GATE1 SOURCE1 DD1 OV1 FB1 PWR GOOD 1 ON GPIO1 EN1 SDA SCL ADIN1 ALERT TIMER CONFIG ADR0 LTC4222 NC ADR1 SS ADR2 ADIN2 INTV CC EN2 GND GPIO2 PWR GOOD 2 OV2 FB2 – UV2 V SENSE2 GATE2 SOURCE2 DD2 10Ω Si7336ADP 6mΩ ...