|
|
PDF LTC3890-2 Data sheet ( Hoja de datos )
| Número de pieza | LTC3890-2 | |
| Descripción | 2-Phase Synchronous Step-Down DC/DC Controller | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTC3890-2 (archivo pdf) en la parte inferior de esta página. Total 30 Páginas | ||
|
No Preview Available !
LTC3890-2
FEATURES
n Wide VIN Range: 4V to 60V (65V Abs Max)
n Low Operating IQ: 50μA (One Channel On)
n Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
n RSENSE or DCR Current Sensing
n Out-of-Phase Controllers Reduce 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 Tracking
n Power Good Output Voltage Monitors
n Low Shutdown IQ : < 14μA
n Internal LDO Powers Gate Drive from VIN or EXTVCC
n Small Low Profile (0.75mm) 5mm × 5mm QFN Package
APPLICATIONS
n Automotive Always-On Systems
n Battery Operated Digital Devices
n Distributed DC Power Systems
60V Low IQ, Dual, 2-Phase
Synchronous Step-Down
DC/DC Controller
DESCRIPTION
The LTC®3890-2 is a high performance dual step-down
switching regulator DC/DC controller that drives all
N-channel synchronous power MOSFET stages. A constant
frequency current mode architecture allows a phase-
lockable frequency of up to 850kHz. Power loss and noise
due to the ESR of the input capacitor are minimized by
operating the two controller output stages out-of-phase.
The 50μA no-load quiescent current extends operating run
time in battery-powered systems. OPTI-LOOP® compensa-
tion allows the transient response to be optimized over a
wide range of output capacitance and ESR values. A wide
4V to 60V input supply range encompasses a wide range
of intermediate bus voltages and battery chemistries.
Independent TRACK/SS pins for each controller ramp the
output voltages during start-up. Current mode control limits
the inductor current during short-circuit conditions. The
PLLIN/MODE pin selects among Burst Mode operation,
pulse-skipping mode, or continuous conduction mode at
light loads. For versions with different and/or additional
features, see the LTC3890 family summary, Table 1, in the
Pin Functions section of this data sheet.
L, LT, LTC, LTM, Linear Technology, Burst Mode, OPTI-LOOP, PolyPhase 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, 6100678, 6144194, 6177787, 6304066, 6580258, 7230497.
TYPICAL APPLICATION
VOUT1
3.3V
5A
High Efficiency Dual 8.5V/3.3V Output Step-Down Converter
4.7μH
0.1μF
VIN
TG1
BOOST1
SW1
INTVCC
TG2
BOOST2
SW2
4.7μF
VIN
9V TO 60V
22μF
0.1μF
8μH
BG1 BG2
LTC3890-2
PGND
SENSE1+
SENSE2+
0.008Ω
100k
470μF
31.6k
1000pF
SENSE1–
VFB1
ITH1
SENSE2–
VFB2
ITH2
TRACK/SS1 SGND TRACK/SS2
34.8k 0.1μF
0.1μF
1000pF
34.8k
0.01Ω
100k
10.5k
VOUT2
8.5V
3A
330μF
38902 TA01a
Efficiency and Power Loss
vs Output Current
100
VIN = 12V
90 VOUT = 3.3V
80
10000
1000
70
60 100
50
40 10
30
20 1
10
0
0.0001
0.001 0.01 0.1
1
OUTPUT CURRENT (A)
0.1
10
38902 TA01b
38902f
1
1 page  
LTC3890-2
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VRUN1,2 = 5V, EXTVCC = 0V unless otherwise noted.
(Note 2)
SYMBOL PARAMETER
PGOOD1 and PGOOD2 Outputs
VPGL
IPGOOD
VPG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
tPG Delay for Reporting a Fault
CONDITIONS
IPGOOD = 2mA
VPGOOD = 5V
VFB with Respect to Set Regulated Voltage
VFB Ramping Negative
Hysteresis
VFB with Respect to Set Regulated Voltage
VFB Ramping Positive
Hysteresis
MIN TYP MAX UNITS
0.2 0.4
±1
–13 –10
2.5
–7
7 10 13
2.5
25
V
μA
%
%
%
%
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 LTC3890-2 is tested under pulsed load conditions such that
TJ ≈ TA. The LTC3890E-2 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 LTC3890I-2 is guaranteed
over the –40°C to 125°C operating junction temperature range, the
LTC3890H-2 is guaranteed over the –40°C to 150°C operating junction
temperature range and the LTC3890MP-2 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: TJ is calculated from the ambient temperature TA and power
dissipation PD according to the following formula:
TJ = TA + (PD • 34°C/W)
Note 4: The LTC3890-2 is tested in a feedback loop that servos VITH1,2 to a
specified voltage and measures the resultant VFB. 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-2/
LTC3890I-2, 150°C for the LTC3890H-2/LTC3890MP-2). For the LTC3890MP-2,
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 IMAX (See Minimum On-Time
Considerations in the Applications Information section).
38902f
5
5 Page 
FUNCTIONAL DIAGRAM
PGOOD1
27
PGOOD2
14
FREQ
2
20μA
0.88V
VFB1
PHASMD
3
CLKOUT
4
0.72V
0.88V
VFB2
0.72V
VCO CLK2
CLK1
PFD
CLP
PLLIN/MODE
5
ILIM
28
VIN
22
EXTVCC
20
+
4.7V –
100k
SYNC
DET
CURRENT
LIMIT
5.1V
LDO
EN
5.1V
LDO
EN
33 SGND
19 INTVCC
LTC3890-2
DUPLICATE FOR SECOND
CONTROLLER CHANNEL
BOOST
24, 17
INTVCC VIN
DB
DROP
OUT
DET
BOT
SQ
TOP ON
TG
26, 15
TOP
SW
25, 16
RQ
SHDN
SWITCH
LOGIC
BOT
INTVCC
BG
23, 18
0.425V +
–
SLEEP
PGND
21
CB
CIN
COUT
L RSENSE
ICMP
–+
2.7V
0.65V
+ IR
+– –
3mV
SENSE+
32, 10
SENSE–
1, 9
SLOPE COMP
7μA (RUN1)
0.5μA (RUN2)
11V
VFB
31, 11
EA 0.80V
TRACK/SS
ITH
30, 12
RB
RA
CC
TRACK/SS
1μA 29, 13
CC2 RC
SHDN
CSS
RUN
7, 8
38902 FD
VOUT
38902f
11
11 Page | ||
| Páginas | Total 30 Páginas | |
| PDF Descargar | [ Datasheet LTC3890-2.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTC3890-1 | 2-Phase Synchronous Step-Down DC/DC Controller |  Linear |
| LTC3890-2 | 2-Phase Synchronous Step-Down DC/DC Controller | Linear Technology |
| LTC3890-3 | 2-Phase Synchronous Step-Down DC/DC Controller | Linear |
| 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 |