LTC3890
The LTC3890 is an electronic component from Analog Devices. View the full LTC3890 datasheet below including electrical characteristics, absolute maximum ratings.
Manufacturer
Analog Devices
Overview
Part: LTC3890 — Analog Devices (Linear Technology)
Type: Dual, 2-Phase Synchronous Step-Down DC/DC Controller
Description: A high performance dual step-down switching regulator DC/DC controller that drives all N-channel synchronous power MOSFET stages, featuring a wide 4V to 60V input supply range, 50μA low operating quiescent current, and a wide 0.8V to 24V output voltage range.
Operating Conditions:
- Supply voltage: 4V to 60V
- Operating junction temperature: -40°C to 150°C (LTC3890H, LTC3890MP)
- Output voltage range: 0.8V to 24V
- Phase-lockable frequency: 75kHz to 850kHz
Absolute Maximum Ratings:
- Max supply voltage: 65V
- Max junction temperature: 150°C
- Max storage temperature: -65°C to 150°C
Key Specs:
- Regulated Feedback Voltage (V FB1,2): 0.800V (typ)
- Input DC Supply Current (Sleep Mode, One Channel On): 50 μA (typ)
- Input DC Supply Current (Shutdown): 14 μA (typ)
- Undervoltage Lockout (INTV CC Ramping Up): 3.92V (typ)
- Maximum Current Sense Threshold (V FB1,2 = 0.7V, I LIM = FLOAT): 75 mV (typ)
- Minimum On-Time: 95 ns (typ)
- Internal V CC Voltage (V INTVCCVIN, 6V < V IN < 60V): 5.1V (typ)
- Synchronizable Frequency: 75 kHz to 850 kHz
Features:
- Wide V IN Range: 4V to 60V
- Low Operating I Q : 50μA (One Channel On)
- Wide Output Voltage Range: 0.8V ≤ V OUT ≤ 24V
- RSENSE or DCR Current Sensing
- Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- Phase-Lockable Frequency (75kHz to 850kHz)
- Programmable Fixed Frequency (50kHz to 900kHz)
- Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode Operation at Light Loads
- Selectable Current Limit
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Output Voltage Soft-Start or Tracking
- Power Good Output Voltage Monitors
- Output Overvoltage Protection
- Low Shutdown I Q : < 14μA
- Internal LDO Powers Gate Drive from V IN or EXTV CC
- No Current Foldback During Start-Up
- Small Low Profile (0.75mm) 5mm × 5mm QFN Package
- AEC-Q100 Qualified for Automotive Applications
Applications:
- Automotive Always-On Systems
- Battery Operated Digital Devices
- Distributed DC Power Systems
Package:
- 32-Lead (5mm × 5mm) Plastic QFN
Features
- n Wide V IN Range: 4V to 60V (65V Abs Max)
- n Low Operating I Q : 50μA (One Channel On)
- n Wide Output Voltage Range: 0.8V ≤ V OUT ≤ 24V
- n RSENSE or DCR Current Sensing
- n Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- n Phase-Lockable Frequency (75kHz to 850kHz)
- n Programmable Fixed Frequency (50kHz to 900kHz)
- n Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode ® Operation at Light Loads
- n Selectable Current Limit
- n Very Low Dropout Operation: 99% Duty Cycle
- n Adjustable Output Voltage Soft-Start or T racking
- n Power Good Output Voltage Monitors
- n Output Overvoltage Protection
- n Low Shutdown I Q : < 14μA
- n Internal LDO Powers Gate Drive from V IN or EXTV CC
- n No Current Foldback During Start-Up
- n Small Low Profile (0.75mm) 5mm × 5mm QFN Package
- n AEC-Q100 Qualified for Automotive Applications
Applications
- n Automotive Always-On Systems
- n Battery Operated Digital Devices
- n Distributed DC Power Systems
Pin Configuration
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at T A = 25°C. V IN = 12V , V RUN1,2 = 5V , EXTV CC = 0V unless otherwise noted. (Note 2)
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V
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| SYMBOL | PARAMETER | CONDITIONS | MIN | TYP | MAX | UNITS | |
|---|---|---|---|---|---|---|---|
| V IN | Input Supply Operating Voltage Range | 4 | 60 | V | |||
| V FB1,2 | Regulated Feedback Voltage | (Note 4) I TH1,2 Voltage = 1.2V -40°C to 85°C, All Grades LTC3890E, LTC3890I LTC3890H, LTC3890MP | l l | 0.792 0.788 0.786 | 0.800 0.800 0.800 | 0.808 0.812 0.812 | V V V |
| I FB1,2 | Feedback Current | (Note 4) | ±5 | ±50 | nA | ||
| V REFLNREG | Reference Voltage Line Regulation | (Note 4) V IN = 4.5V to 60V | 0.002 | 0.02 | %/V | ||
| V LOADREG | Output Voltage Load Regulation | (Note 4) Measured in Servo Loop, ∆ ITH Voltage = 1.2V to 0.7V | l | 0.01 | 0.1 | % | |
| g m1,2 | Transconductance Amplifier g m | (Note 4) I TH1,2 = 1.2V , Sink/Source = 5μA | mmho | ||||
| I | (Note 5) | 2 | |||||
| Q | Input DC Supply Current | ||||||
| Pulse-Skipping or Forced Continuous Mode (One Channel On) | RUN1 = 5V and RUN2 = 0V , V FB1 = 0.83V or RUN1 = 0V and RUN2 = 5V , V FB2 = 0.83V | 1.3 | mA | ||||
| Pulse-Skipping or Forced Continuous Mode (Both Channels On) | RUN1,2 = 5V , V FB1,2 = 0.83V (No Load) | 2 | mA | ||||
| Sleep Mode (One Channel On) | RUN1 = 5V and RUN2 = 0V , V FB1 = 0.83V (No Load) RUN1 = 0V and RUN2 = 5V , V FB2 = 0.83V (No Load) | 50 | 75 | μA | |||
| Sleep Mode (Both Channels On) | RUN1,2 = 5V , V FB1,2 = 0.83V (No Load) | 60 | 100 | μA | |||
| Shutdown | RUN1,2 = 0V | 14 | 25 | μA | |||
| UVLO | Undervoltage Lockout | INTV CC Ramping Up INTV CC Ramping Down | l l | 3.6 | 3.92 3.80 | 4.2 4.0 | V V |
| Feedback Overvoltage Protection | Measured at V FB1,2 , Relative to Regulated V FB1,2 | 7 | 10 | 13 | % | ||
| I SENSE + | SENSE + Pin Current | Each Channel | ±1 | μA | |||
| I SENSE - | SENSE - Pins Current | Each Channel V SENSE - < INTV CC - 0.5V V SENSE - > INTV CC + 0.5V | μA | ||||
| Maximum TG1,2 Duty Factor | 700 | ±1 | μA | ||||
| I TRACK/SS1,2 | Soft-Start Charge Current | In Dropout V TRACK/SS1,2 = 0V | 98 | 99 | 1.4 | % | |
| V RUN1 V RUN2 | RUN1 Pin On Threshold | V RUN1 Rising V Rising | l | 0.7 1.15 | 1.0 1.21 | 1.27 | μA V |
| RUN2 Pin On Threshold RUN1,2 Pin Hysteresis | RUN2 | l | 1.20 | 1.25 50 | 1.30 | V mV | |
| V SENSE(MAX) | Maximum Current Sense Threshold | V FB1,2 = 0.7V , V SENSE1 -, 2 - = 3.3V , I LIM = 0 V FB1,2 = 0.7V , V SENSE1 -, 2 - = 3.3V , I LIM = INTV CC V FB1,2 = 0.7V , V SENSE1 -, 2 - = 3.3V , I LIM = FLOAT | l l l | 22 43 64 | 30 50 75 | 36 57 85 | mV mV mV |
| Gate Driver | Gate Driver TG1,2 Pull-Up On-Resistance TG1,2 Pull-Down On-Resistance BG1,2 Pull-Up On-Resistance BG1,2 Pull-Down On-Resistance | Gate Driver | Gate Driver | Gate Driver | Gate Driver 2.5 1.5 2.4 1.1 | Gate Driver | Gate Driver Ω Ω Ω Ω |
| TG1,2 t r | TG Transition Time: Rise Time Fall Time | (Note 6) C LOAD = 3300pF C = 3300pF | 25 | ns | |||
| TG1,2 t f | Transition Time: Rise Time | LOAD (Note 6) C LOAD = 3300pF | 16 | ns | |||
| BG1,2 t r BG1,2 t f | BG Fall Time | C LOAD = 3300pF | 28 13 | ns ns |
Rev . D
Electrical Characteristics
The l denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at T A = 25°C. V IN = 12V , V RUN1,2 = 5V , EXTV CC = 0V unless otherwise noted. (Note 2)
| SYMBOL | PARAMETER | CONDITIONS | MIN | TYP | MAX | UNITS | |
|---|---|---|---|---|---|---|---|
| TG/BG t 1D | Top Gate Off to Bottom Gate On Delay Synchronous Switch-On Delay Time | C LOAD = 3300pF Each Driver | 30 | ns | |||
| BG/TG t 1D | Bottom Gate Off to Top Gate On Delay Top Switch-On Delay Time | C LOAD = 3300pF Each Driver | 30 | ns | |||
| t ON(MIN) | Minimum On-Time | (Note 7) | 95 | ns | |||
| INTV CC Linear Regulator | INTV CC Linear Regulator | INTV CC Linear Regulator | INTV CC Linear Regulator | INTV CC Linear Regulator | INTV CC Linear Regulator | INTV CC Linear Regulator | INTV CC Linear Regulator |
| V INTVCCVIN | Internal V CC Voltage | 6V < V IN < 60V , V EXTVCC = 0V | 4.85 | 5.1 | 5.35 | V | |
| V LDOVIN | INTV CC Load Regulation | I CC = 0mA to 50mA, V EXTVCC = 0V | 0.7 | 1.1 | % | ||
| V INTVCCEXT | Internal V CC Voltage | 6V < V EXTVCC < 13V | 4.85 | 5.1 | 5.35 | V | |
| V LDOEXT | INTV CC Load Regulation | I CC = 0mA to 50mA, V EXTVCC = 8.5V | 0.6 | 1.1 | % | ||
| V EXTVCC | EXTV CC Switchover Voltage | EXTV CC Ramping Positive | 4.5 | 4.7 | 4.9 | V | |
| V LDOHYS | EXTV CC Hysteresis | 250 | mV | ||||
| Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop | Oscillator and Phase-Locked Loop |
| f 25kΩ | Programmable Frequency | R FREQ = 25k, PLLIN/MODE = DC Voltage | 105 | kHz | |||
| f 65kΩ | Programmable Frequency | R FREQ = 65k, PLLIN/MODE = DC Voltage | 375 | 440 | 505 | kHz | |
| f 105kΩ | Programmable Frequency | R FREQ = 105k, PLLIN/MODE = DC Voltage | 835 | kHz | |||
| f LOW | Low Fixed Frequency | V FREQ = 0V , PLLIN/MODE = DC Voltage | 320 | 350 | 380 | kHz | |
| f HIGH | High Fixed Frequency | V FREQ = INTV CC , PLLIN/MODE = DC Voltage | 485 | 535 | 585 | kHz | |
| f SYNC | Synchronizable Frequency | PLLIN/MODE = External Clock | l | 75 | 850 | kHz | |
| PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs | PGOOD1 and PGOOD2 Outputs |
| V PGL | PGOOD Voltage Low | I PGOOD = 2mA | 0.2 | 0.4 | V | ||
| I PGOOD | PGOOD Leakage Current | V PGOOD = 5V | ±1 | μA | |||
| V PG | PGOOD Trip Level | V FB with Respect to Set Regulated Voltage V FB Ramping Negative Hysteresis | -13 | -10 2.5 | -7 | % % | |
| V FB with Respect to Set Regulated Voltage V FB Ramping Positive Hysteresis | 7 | 10 2.5 | 13 | % % | |||
| t PG | Delay for Reporting a Fault | 25 | μs |
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Ratings for extended periods may affect device reliability and lifetime.
Note 2: The LTC3890 is tested under pulsed load conditions such that T J ≈ T A . The L TC3890E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the -40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The L TC3890I is guaranteed over the -40°C to 125°C operating junction temperature range, the LTC3890H is guaranteed over the -40°C to 150°C operating junction temperature range and the LTC3890MP is tested and guaranteed over the -55°C to 150°C operating junction temperature range.
High junction temperatures degrade operating lifetimes; operating lifetime is derated for junction temperatures greater than 125°C. Note that the maximum ambient temperature consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors.
Note 3: T J is calculated from the ambient temperature T A and power dissipation P D according to the following formula:
Note 4: The LTC3890 is tested in a feedback loop that servos V ITH1,2 to a specified voltage and measures the resultant V FB . The specification at 85°C is not tested in production and is assured by design, characterization and correlation to production testing at other temperatures (125°C for the LTC3890E/LTC3890I, 150°C for the LTC3890H/LTC3890MP). For the LTC3890MP , the specification at -40°C is not tested in production and is assured by design, characterization and correlation to production testing at -55°C.
Note 5: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency. See Applications information.
Note 6: Rise and fall times are measured using 10% and 90% levels. Delay times are measured using 50% levels.
Note 7: The minimum on-time condition is specified for an inductor peak-to-peak ripple current ≥ 40% of I MAX (See Minimum On-Time Considerations in the Applications Information section).
Absolute Maximum Ratings
(Note 1)
| Input Supply Voltage (V IN )......................... | -0.3V to 65V |
|---|---|
| Topside Driver Voltages BOOST1, BOOST2 | .................................-0.3V to 71V |
| Switch Voltage (SW1, SW2) | .........................-5V to 65V |
| (BOOST1-SW1), (BOOST2-SW2) | ................ -0.3V to 6V |
| RUN1, RUN2 | -0.3V to 8V |
| ............................................... Maximum Current Sourced into Pin from Source > 8V .....................................................100μA | |
| SENSE1 + , SENSE2 + , SENSE1 - SENSE2 - Voltages ..................................... | -0.3V to 28V |
| PLLIN/MODE, INTV CC Voltages | ................... -0.3V to 6V |
| FREQ Voltage ........................................-0.3V | to INTV CC |
| I LIM , PHASMD Voltages | .......................-0.3V to INTV CC |
| EXTV CC | ..................................................... -0.3V to 14V |
| ITH1, ITH2, V FB1 , V FB2 Voltages................... | -0.3V to 6V |
| PGOOD1, PGOOD2 Voltages | ....................... -0.3V to 6V |
| TRACK/SS1, TRACK/SS2 Voltages | ............. -0.3V to 6V |
| Operating Junction Temperature Range | (Notes 2, 3) |
| LTC3890E, LTC3890I......................... | -40°C to 125°C |
| LTC3890H..........................................-40°C | to 150°C |
| LTC3890MP....................................... | -55°C to 150°C |
| Storage Temperature Range | ..................-65°C to 150°C |
Typical Application
High Efficiency Dual 8.5V/3.3V Output Step-Down Converter
Related Variants
The following components are covered by the same datasheet.
| Part Number | Manufacturer | Package |
|---|---|---|
| LTC3890-1 | Analog Devices | — |
| LTC3890E | Analog Devices | — |
| LTC3890EUH | Analog Devices | 32-Lead (5mm × 5mm) Plastic QFN |
| LTC3890H | Analog Devices | — |
| LTC3890HUH | Analog Devices | — |
| LTC3890I | Analog Devices | — |
| LTC3890IUH | Analog Devices | — |
| LTC3890MP | Analog Devices | — |
| LTC3890MPUH | Analog Devices | — |
| LTC3890XIGN-1 | Analog Devices | — |
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