|
|
PDF LTC3892-1 Data sheet ( Hoja de datos )
| Número de pieza | LTC3892-1 | |
| Descripción | 2-Phase Synchronous Step-Down DC/DC Controller | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTC3892-1 (archivo pdf) en la parte inferior de esta página. Total 30 Páginas | ||
|
No Preview Available !
Features
n Wide VIN Range: 4.5V to 60V (65V Abs Max)
n Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 99% • VIN
n Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE)
n No External Bootstrap Diodes Required
n Low Operating IQ: 29μA (One Channel On)
n Selectable Gate Drive UVLO Thresholds
n Out-of-Phase Operation Reduces 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 (LTC3892)
n Very Low Dropout Operation: 99% Duty Cycle
n Power Good Output Voltage Monitors (LTC3892)
n Low Shutdown IQ: 3.6μA
n Small 32-Lead 5mm × 5mm QFN Package (LTC3892)
n Small 28-Lead TSSOP Package (LTC3892-1)
Applications
n Automotive and Industrial Power Systems
n Distributed DC Power Systems
n High Voltage Battery Operated Systems
LTC3892/LTC3892-1
60V Low IQ, Dual, 2-Phase
Synchronous Step-Down
DC/DC Controller
Description
The LTC®3892/LTC3892-1 is a high performance dual
step-down DC/DC switching regulator controller that
drives all N-channel synchronous power MOSFET stages.
Power loss and noise are minimized by operating the two
controller output stages out-of-phase.
The gate drive voltage can be programmed from 5V to
10V to allow the use of logic or standard-level FETs and
to maximize efficiency. Internal switches in the top gate
drivers eliminate the need for external bootstrap diodes.
A wide 4.5V to 60V input supply range encompasses a wide
range of intermediate bus voltages and battery chemistries.
Output voltages up to 99% of VIN can be regulated. OPTI-
LOOP® compensation allows the transient response and
loop stability to be optimized over a wide range of output
capacitance and ESR values.
The 29μA no-load quiescent current extends operating
run time in battery powered systems. For a comparision
of the LTC3892 to the LTC3892-1, see Table 1 in the Pin
Functions section of this data sheet.
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are
registered trademarks of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620,
6144194, 6177787, 6580258.
Typical Application
High Efficiency Dual 5V/12V Output Step-Down Converter
VIN
12.5V TO 60V
47µF
VO5UVT1
8A
220µF
5mΩ 5.6µH
0.1µF
RUN1 VIN RUN2
TG1
BOOST1
TG2
BOOST2
SW1 SW2
BG1 BG2
LTC3892
0.1µF
15µH 8mΩ
7.5k
100pF
2.2nF
1nF
0.1µF
SENSE1+
SENSE1–
VFB1
ITH1
TRACK/SS1
VPRG1
SENSE2+
SENSE2–
VFB2
ITH2
TRACK/SS2
DRVSET
DRVUV
INTVCC GND DRVCC
0.1µF
4.7µF
1nF
34.8k
0.1µF 100pF
1nF
V1O2UVT2
5A
150µF
100k
7.15k
3892 TA01
For more information www.linear.com/LTC3892
EEffffiicciieenncycyvsvOsutOpuuttpCuurtreCnut rrent
96
VIN = 12V
95 VOUT = 5V
Burst Mode OPERATION
94
93
92
91
90
89
88
0.01
GATE DRIVE
DRVCC=5V
DRVCC=6V
DRVCC=8V
DRVCC=10V
0.1 1
LOAD CURRENT (A)
10
3892 F01b
38921f
1
1 page  
LTC3892/LTC3892-1
E lectrical Characteristics The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 12V, VRUN1,2 = 5V, VEXTVCC = 0V, VDRVSET = 0V,
VPRG1 = FLOAT unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX
VRUN1,2 ON
VRUN1,2 Hyst
VSENSE(MAX)
RUN Pin On Threshold
RUN Pin Hysteresis
Maximum Current Sense Threshold
VSENSE(MATCH)
Matching Between
VSENSE2(MAX)
VSENSE1(MAX)
and
Gate Driver
VRUN1, VRUN2 Rising
VFB1,2 = 0.7V, VSENSE1,2– = 3.3V
ILIM = FLOAT (LTC3892) or LTC3892-1
IILLIIMM
=
=
0V (LTC3892 Only)
INTVCC (LTC3892 Only)
VFBIL1I,M2 ==0F.L7OVA, TVS(ELNTSCE318,29–2=)
3.3V
or LTC3892-1
ILIM = 0V (LTC3892 Only)
ILIM = INTVCC (LTC3892 Only)
l 1.22 1.275 1.33
75
l 66
l 43
l 90
75 84
50 58
100 109
l –8
l –8
l –8
0
0
0
8
8
8
TG1,2
Pull-Up On-Resistance
Pull-Down On-Resistance
VDRVSET = INTVCC
2.2
1.0
BG1,2
Pull-Up On-Resistance
Pull-Down On-Resistance
VDRVSET = INTVCC
2.2
1.0
BDSW1,2
TG1,2 tr
TG1,2 tf
BG1,2 tr
BG1,2 tf
TG/BG t1D
BOOST to DRVCC Switch On-Resistance
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
VSW = 0V, VDRVSET = INTVCC
(Note 6) VDRVSET = INTVCC
CLOAD = 3300pF
CLOAD = 3300pF
(Note 6) VDRVSET = INTVCC
CLOAD = 3300pF
CLOAD = 3300pF
CLOAD = 3300pF Each Driver, VDRVSET = INTVCC
3.7
25
15
25
15
55
BG/TG t1D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
CLOAD = 3300pF Each Driver, VDRVSET = INTVCC
50
tON(MIN)1,2
TG Minimum On-Time
DRVCC Linear Regulator
VDRVCC(INT) DRVCC Voltage from Internal VIN LDO
VLDOREG(INT)
VDRVCC(EXT)
DRVCC Load Regulation from VIN LDO
DRVCC Voltage from Internal EXTVCC LDO
VLDOREG(EXT)
VEXTVCC
DRVCC Load Regulation from Internal
EXTVCC LDO
EXTVCC LDO Switchover Voltage
VLDOHYS
VDRVCC(50kΩ)
VDRVCC(70kΩ)
VDRVCC(90kΩ)
EXTVCC Hysteresis
Programmable DRVCC
Programmable DRVCC
Programmable DRVCC
(Note 7) VDRVSET = INTVCC
VEXTVCC = 0V
7V < VIN < 60V, DRVSET = 0V
11V < VIN < 60V, DRVSET = INTVCC
ICC = 0mA to 50mA, VEXTVCC = 0V
7V < VEXTVCC < 13V, DRVSET = 0V
11V < VEXTVCC < 13V, DRVSET = INTVCC
ICC = 0mA to 50mA, VEXTVCC = 8.5V,
VDRVSET = 0V
EXTVCC Ramping Positive
DRVUV = 0V
DRVUV = INTVCC
RDRVSET = 50kΩ, VEXTVCC = 0V
RDRVSET = 70kΩ, VEXTVCC = 0V
RDRVSET = 90kΩ, VEXTVCC = 0V
80
5.8 6.0 6.2
9.6 10.0 10.4
0.9 2.0
5.8 6.0 6.2
9.6 10.0 10.4
0.7 2.0
4.5 4.7 4.9
7.4 7.7 8.0
250
5.0
6.4 7.0 7.6
9.0
UNITS
V
mV
mV
mV
mV
mV
mV
mV
Ω
Ω
Ω
Ω
Ω
ns
ns
ns
ns
ns
ns
ns
V
V
%
V
V
%
V
V
mV
V
V
V
For more information www.linear.com/LTC3892
38921f
5
5 Page 
LTC3892/LTC3892-1
Pin Functions (LTC3892 (QFN)/LTC3892-1 (TSSOP))
BG1, BG2 (Pins 23, 19/Pins 24, 20): High Current Gate
Drives for Bottom N-Channel MOSFETs. Voltage swing at
these pins is from ground to DRVCC.
BOOST1,BOOST2 (Pins 24, 18/Pins 25, 19):Bootstrapped
Supplies to the Topside Floating Drivers. Capacitors are
connected between the BOOST and SW pins. Voltage
swing at BOOST1 and BOOST2 pins is from approximately
DRVCC to (VIN1,2 + DRVCC).
SW1, SW2 (Pins 25, 17/Pins 26, 18): Switch Node Con-
nections to Inductors.
TG1, TG2 (Pins 26, 16/Pins 27, 17): High Current Gate
Drives for Top N-Channel MOSFETs. These are the outputs
of floating drivers with a voltage swing equal to DRVCC
superimposed on the switch node voltage SW.
TRACK/SS1, TRACK/SS2 (Pins 27, 15/Pins 28, 16):
External Tracking and Soft-Start Input. The LTC3892/
LTC3892-1 regulates the negative input (EA–) of the er-
ror amplifier to the smaller of 0.8V or the voltage on the
TRACK/SS pin. An internal 10µA pull-up current source
is connected to this pin. A capacitor to ground at this pin
sets the ramp time at start-up to the final regulated output
voltage. Alternatively, a resistor divider on another sup-
ply connected to the TRACK/SS pin allows the LTC3892/
LTC3892-1 output voltage to track the other supply during
start-up. The TRACK/SS pin is pulled low in shutdown or
in undervoltage lockout.
VPRG1 (Pin 28/NA): Channel 1 Output Voltage Control Pin.
This pin sets channel 1 to adjustable output mode using
external feedback resistors or fixed 3.3V/5V output mode.
Floating this pin allows the output to be programmed from
0.8V to 60V with an external resistor divider, regulating
VFB1 to 0.8V. This pin is only available on the LTC3892,
not the LTC3892-1.
ITH1, ITH2 (Pins 29, 12/Pins 1, 13): Error Amplifier
Outputs and Switching Regulator Compensation Points.
Each associated channel’s current comparator trip point
increases with this control voltage.
VFB1 (Pin 30/Pin 2): For the LTC3892-1, this pin receives
the remotely sensed feedback voltage for channel 1 from
an external resistor divider across the output.
For the LTC3892, if the VPRG1 pin is floating, the VFB1 pin
receives the remotely sensed feedback voltage for chan-
nel 1 from an external resistor divider across the output.
If VPRG1 is tied to GND or INTVCC, the VFB1 pin receives
the remotely sensed output voltage directly.
SENSE1+, SENSE2+ (Pins 31, 10/Pins 3, 11): The (+)
Input to the Differential Current Comparators. The ITH pin
voltage and controlled offsets between the SENSE– and
SENSE+ pins in conjunction with RSENSE set the current
trip threshold.
SENSE1–, SENSE2– (Pins 32, 9/Pins 4, 10): The (–) Input
totheDifferential CurrentComparators. WhenSENSE1,2–is
greater than INTVCC, then SENSE1,2– pin supplies current
to the current comparator.
GND (Exposed Pad Pin 33/Exposed Pad Pin 29): Ground.
The exposed pad must be soldered to the PCB for rated
electrical and thermal performance.
Table 1. Summary of the Differences Between the LTC3892 and LTC3892-1
LTC3892
ILIM pin for selectable current sense voltage? Yes; 50mV, 75mV, or 100mV
VPRG1 pin for fixed or adjustable VOUT1?
Yes; fixed 3.3V or 5V (with internal resistor divider)
or adjustable with external resistor divider
Independent PGOOD output for each channel? Yes; PGOOD1 and PGOOD2
Package
32-Pin 5mm × 5mm QFN (UH32)
LTC3892-1
No; fixed 75mV
No; only adjustable with external resistor divider
No PGOOD function
28-Lead TSSOP (FE28)
For more information www.linear.com/LTC3892
38921f
11
11 Page | ||
| Páginas | Total 30 Páginas | |
| PDF Descargar | [ Datasheet LTC3892-1.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTC3892-1 | 2-Phase Synchronous Step-Down DC/DC Controller | Linear Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |