OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LTC1628IG-PG#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P30P31-P32
1
LTC1628/LTC1628-PG
1628fb
High Efficiency, 2-Phase
Synchronous Step-Down Switching Regulators
Figure 1. High Efficiency Dual 5V/3.3V Step-Down Converter
■
Out-of-Phase Controllers Reduce Required Input
Capacitance and Power Supply Induced Noise
■
OPTI-LOOP
®
Compensation Minimizes C
OUT
■
±1% Output Voltage Accuracy
■
Dual N-Channel MOSFET Synchronous Drive
■
Power Good Output Voltage Monitor (LTC1628-PG)
■
DC Programmed Fixed Frequency 150kHz to 300kHz
■
Wide V
IN
Range: 3.5V to 36V Operation
■
Very Low Dropout Operation: 99% Duty Cycle
■
Adjustable Soft-Start Current Ramping
■
Foldback Output Current Limiting
■
Latched Short-Circuit Shutdown with Defeat Option
■
Output Overvoltage Protection
■
Remote Output Voltage Sense
■
Low Shutdown I
Q
: 20µA
■
5V and 3.3V Standby Regulators
■
Selectable Constant Frequency or Burst Mode
®
Operation
■
Available in 5mm × 5mm QFN and
28-Pin SSOP Packages
The LTC
®
1628/LTC1628-PG are high performance dual
step-down switching regulator controllers that drive all
N-channel synchronous power MOSFET stages. A con-
stant frequency current mode architecture allows adjust-
ment of the frequency up to 300kHz. Power loss and noise
due to the ESR of the input capacitors are minimized by
operating the two controller output stages out of phase.
OPTI-LOOP compensation allows the transient response
to be optimized over a wide range of output capacitance and
ESR values. The precision 0.8V reference and power good
output indicator are compatible with future microproces-
sor generations, and a wide 3.5V to 30V (36V maximum)
input supply range encompasses all battery chemistries.
A RUN/SS pin for each controller provides both soft-start
and optional timed, short-circuit shutdown. Current
foldback limits MOSFET dissipation during short-circuit
conditions when overcurrent latchoff is disabled. Output
overvoltage protection circuitry latches on the bottom
MOSFET until V
OUT
returns to normal. The FCB mode pin
can select among Burst Mode, constant frequency mode
and continuous inductor current mode or regulate a
secondary winding. The LTC1628-PG includes a power
good output pin that replaces the FLTCPL, fault coupling
control pin of the LTC1628.
■
Notebook and Palmtop Computers, PDAs
■
Battery Chargers
■
Portable Instruments
■
Battery-Operated Digital Devices
■
DC Power Distribution Systems
, LTC and LT are registered trademarks of Linear Technology Corporation.
OPTI-LOOP and Burst Mode are registered trademarks of Linear Technology Corporation.
DESCRIPTIO
U
FEATURES
APPLICATIO S
U
TYPICAL APPLICATIO
U
+
4.7µF
D3
D4
D1
M2
M1
C
B1
, 0.1µF
R2
105k
1%
1000pF
L1
6.3µH
C
C1
220pF
1µF
CERAMIC
C
IN
22µF
50V
CERAMIC
+
C
OUT1
47µF
6V
SP
R
SENSE1
0.01Ω
R1
20k
1%
R
C1
15k
V
OUT1
5V
5A
D2
M4
M3
C
B2
, 0.1µF
R4
63.4k
1%
L2
6.3µH
C
C2
220pF
1000pF
+
C
OUT
56µF
6V
SP
R
SENSE2
0.01Ω
R3
20k
1%
R
C2
15k
V
OUT2
3.3V
5A
TG1 TG2
BOOST1 BOOST2
SW1 SW2
BG1 BG2
SGND PGND
SENSE1
+
SENSE2
+
SENSE1
–
SENSE2
–
V
OSENSE1
V
OSENSE2
I
TH1
I
TH2
V
IN
INTV
CC
RUN/SS1 RUN/SS2
V
IN
5.2V TO 28V
M1, M2, M3, M4: FDS6680A
1628 F01
C
SS1
0.1µF
C
SS2
0.1µF
LTC1628
2
LTC1628/LTC1628-PG
1628fb
ORDER PART
NUMBER
LTC1628CG
LTC1628IG
LTC1628CG-PG
LTC1628IG-PG
Input Supply Voltage (V
IN
).........................36V to –0.3V
Top Side Driver Voltages
(BOOST1, BOOST2) ...................................42V to –0.3V
Switch Voltage (SW1, SW2) .........................36V to –5V
INTV
CC,
EXTV
CC
, RUN/SS1, RUN/SS2, (BOOST1-SW1),
(BOOST2-SW2), PGOOD .............................7V to –0.3V
SENSE1
+
, SENSE2
+
, SENSE1
–
,
SENSE2
–
Voltages........................ (1.1)INTV
CC
to –0.3V
FREQSET, STBYMD, FCB,
FLTCPL Voltage ................................... INTV
CC
to –0.3V
T
JMAX
= 125°C, θ
JA
= 95°C/W
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
G PACKAGE
28-LEAD PLASTIC SSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RUN/SS1
SENSE1
+
SENSE1
–
V
OSENSE1
FREQSET
STBYMD
FCB
I
TH1
SGND
3.3V
OUT
I
TH2
V
OSENSE2
SENSE2
–
SENSE2
+
FLTCPL*
TG1
SW1
BOOST1
V
IN
BG1
EXTV
CC
INTV
CC
PGND
BG2
BOOST2
SW2
TG2
RUN/SS2
*PGOOD ON THE LTC1628-PG
ABSOLUTE AXI U RATI GS
WWWU
PACKAGE/ORDER I FOR ATIO
UU
W
I
TH1,
I
TH2
, V
OSENSE1
, V
OSENSE2
Voltages ...2.7V to –0.3V
Peak Output Current <10µs (TG1, TG2, BG1, BG2) ... 3A
INTV
CC
Peak Output Current ................................ 50mA
Operating Temperature Range
LTC1628C/LTC1628C-PG ........................ 0°C to 85°C
LTC1628I/LTC1628I-PG ..................... –40°C to 85°C
Junction Temperature (Note 2)............................. 125°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
(G Package Only) .................................................. 300°C
(Note 1)
ORDER PART
NUMBER
LTC1628CUH
LTC1628IUH
32 31 30 29 28 27 26 25
9 10 11 12
TOP VIEW
UH PACKAGE
32-LEAD (5mm × 5mm) PLASTIC QFN
13 14 15 16
17
18
19
20
21
22
23
24
8
7
6
5
4
3
2
1V
OSENSE1
FREQSET
STBYMD
FCB
I
TH1
SGND
3.3V
OUT
I
TH2
BOOST1
V
IN
BG1
EXTV
CC
INTV
CC
PGND
BG2
BOOST2
NC
SENSE1
–
SENSE1
+
NC
RUN/SS1
FLTCPL
TG1
SW1
V
OSENSE2
NC
SENSE2
–
SENSE2
+
RUN/SS2
TG2
SW2
NC
The ● denotes the specifications which apply over the full operating
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loops
V
OSENSE1, 2
Regulated Feedback Voltage (Note 3); I
TH1, 2
Voltage = 1.2V ● 0.792 0.800 0.808 V
I
VOSENSE1, 2
Feedback Current (Note 3) –5 –50 nA
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 3.6V to 30V (Note 3) 0.002 0.02 %/V
V
LOADREG
Output Voltage Load Regulation (Note 3)
Measured in Servo Loop; ∆I
TH
Voltage = 1.2V to 0.7V ● 0.1 0.5 %
Measured in Servo Loop; ∆I
TH
Voltage = 1.2V to 2.0V ● –0.1 –0.5 %
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS1, 2
= 5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
Consult LTC Marketing for parts specified with wider operating temperature ranges.
θ
JA
= 34°C/W
EXPOSED PAD IS SGND
(MUST BE SOLDERED TO PCB)
UH PART
MARKING
1628
1628I
3
LTC1628/LTC1628-PG
1628fb
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS1, 2
= 5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
g
m1, 2
Transconductance Amplifier g
m
I
TH1, 2
= 1.2V; Sink/Source 5uA; (Note 3) 1.3 mmho
g
mGBW1, 2
Transconductance Amplifier GBW I
TH1, 2
= 1.2V; (Note 3) 3 MHz
I
Q
Input DC Supply Current (Note 4)
Normal Mode V
IN
= 15V; EXTV
CC
Tied to V
OUT1
; V
OUT1
= 5V 350 µA
Standby V
RUN/SS1, 2
= 0V, V
STBYMD
> 2V 125 µA
Shutdown V
RUN/SS1, 2
= 0V, V
STBYMD
= Open; 20 35 µA
V
FCB
Forced Continuous Threshold ● 0.76 0.800 0.84 V
I
FCB
Forced Continuous Pin Current V
FCB
= 0.85V –0.30 –0.18 –0.1 µA
V
BINHIBIT
Burst Inhibit (Constant Frequency) Measured at FCB pin 4.3 4.8 V
Threshold
UVLO Undervoltage Lockout V
IN
Ramping Down ● 3.5 4 V
V
OVL
Feedback Overvoltage Lockout Measured at V
OSENSE1, 2
● 0.84 0.86 0.88 V
I
SENSE
Sense Pins Total Source Current (Each Channel); V
SENSE1
–
, 2
–
= V
SENSE1
+
, 2
+
= 0V –85 –60 µA
V
STBYMD
MS
Master Shutdown Threshold V
STBYMD
Ramping Down 0.4 0.6 V
V
STBYMD
KA Keep-Alive Power On-Threshold V
STBYMD
Ramping Up, RUN
SS1, 2
= 0V 1.5 2 V
DF
MAX
Maximum Duty Factor In Dropout 98 99.4 %
I
FLTCPL
V
FLTCPL
Input Current 0.5V > V
FLTCPL
–3 µA
LTC1628 Only INTV
CC
– 0.5V < V
FLTCPL
< INTV
CC
3 µA
V
FLTCPL
Fault Coupling Threshold; For FCB Signal and Individual Overcurrent 2 V
LTC1628 Only Faults to Affect Both Controllers
I
RUN/SS1, 2
Soft-Start Charge Current V
RUN/SS1, 2
= 1.9V 0.5 1.2 µA
V
RUN/SS1, 2
ON RUN/SS Pin ON Threshold V
RUN/SS1,
V
RUN/SS2
Rising 1.0 1.5 1.9 V
V
RUN/SS1, 2
LT RUN/SS Pin Latchoff Arming Threshold V
RUN/SS1,
V
RUN/SS2
Rising from 3V 4.1 4.5 V
I
SCL1, 2
RUN/SS Discharge Current Soft Short Condition V
OSENSE1, 2
= 0.5V; 0.5 2 4 µA
V
RUN/SS1, 2
= 4.5V
I
SDLHO
Shutdown Latch Disable Current V
OSENSE1, 2
= 0.5V 1.6 5 µA
V
SENSE(MAX)
Maximum Current Sense Threshold V
OSENSE1, 2
= 0.7V,V
SENSE1
–
, 2
– = 5V ● 62 75 88 mV
V
OSENSE1, 2
= 0.7V,V
SENSE1
–
, 2
– = 5V, LTC1628 Only 65 75 85 mV
TG Transition Time: (Note 5)
TG1, 2 t
r
Rise Time C
LOAD
= 3300pF 50 90 ns
TG1, 2 t
f
Fall Time C
LOAD
= 3300pF 50 90 ns
BG Transition Time: (Note 5)
BG1, 2 t
r
Rise Time C
LOAD
= 3300pF 40 90 ns
BG1, 2 t
f
Fall Time C
LOAD
= 3300pF 40 80 ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time C
LOAD
= 3300pF Each Driver 90 ns
BG/TG t
2D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time C
LOAD
= 3300pF Each Driver 90 ns
t
ON(MIN)
Minimum On-Time Tested with a Square Wave (Note 6) 180 ns
INTV
CC
Linear Regulator
V
INTVCC
Internal V
CC
Voltage 6V < V
IN
< 30V, V
EXTVCC
= 4V 4.8 5.0 5.2 V
V
LDO
INT INTV
CC
Load Regulation I
CC
= 0 to 20mA, V
EXTVCC
= 4V 0.2 1.0 %
V
LDO
EXT EXTV
CC
Voltage Drop I
CC
= 20mA, V
EXTVCC
= 5V, LTC1628 120 240 mV
V
LDO
EXT-PG EXTV
CC
Voltage Drop I
CC
= 20mA, V
EXTVCC
= 5V, LTC1628-PG 80 160 mV
V
EXTVCC
EXTV
CC
Switchover Voltage I
CC
= 20mA, EXTV
CC
Ramping Positive ● 4.5 4.7 V
V
LDOHYS
EXTV
CC
Hysteresis 0.2 V
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P30P31-P32

LTC1628IG-PG#PBF

Mfr. #:
Buy LTC1628IG-PG#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators Dual 2-phase Step-dn + Pgood
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet