LTC3834EDHC-1#TRPBF
Analog Devices Inc.
IC REG CTRLR BUCK 16-DFN
En stock4769 pcs
Enable, Soft Start, Tracking
1
99.4%
Yes
No
-
Buck
LTC3834
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
16-WFDFN Exposed Pad
16-DFN (5x3)
Step-Down
250kHz ~ 530kHz
1
Positive
4V ~ 36V
RFQ
ISL6522IB
Renesas Electronics America Inc
IC REG CTRLR BUCK 14SOIC
En stock5150 pcs
Enable, Frequency Control, Phase Control, Soft Start
1
100%
Yes
No
-
Buck
ISL6522
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
14-SOIC (0.154', 3.90mm Width)
14-SOIC
Step-Down
200kHz
1
Positive
10.8V ~ 13.2V
RFQ
XC9252C08AVR-G
Torex Semiconductor Ltd
IC REG CTRLR BUCK 16TSSOP
En stock19345 pcs
Current Limit, Enable, Frequency Control, Power Good, Soft Start
1
100%
No
No
-
Buck
XC9252
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 105°C (TA)
Surface Mount
16-LSSOP (0.173", 4.40mm Width)
16-TSSOP
Step-Down
280kHz ~ 550kHz
1
Positive
3V ~ 30V
RFQ
UC3845DR2G
onsemi
IC REG CTRLR BOOST/FLYBK 14SOIC
En stock7340 pcs
Frequency Control
1
48%
No
No
-
Boost, Flyback
UC3845
Tape & Reel (TR)
Transistor Driver
-
0°C ~ 70°C (TA)
Surface Mount
14-SOIC (0.154', 3.90mm Width)
14-SOIC
Step-Up, Step-Up/Step-Down
Up to 500kHz
1
Positive, Isolation Capable
7.6V ~ 30V
RFQ
UC3843BNG
onsemi
IC REG CTRLR FLYBACK 8DIP
En stock74860 pcs
Frequency Control
1
96%
No
No
-
Boost, Flyback
UC3843
Tube
Transistor Driver
-
0°C ~ 70°C (TA)
Through Hole
8-DIP (0.300", 7.62mm)
8-PDIP
Step-Up, Step-Up/Step-Down
Up to 500kHz
1
Positive, Isolation Capable
7.6V ~ 30V
RFQ
HIP6302VCB-T
Renesas Electronics America Inc
IC REG CTRLR BUCK 16SOIC
En stock14510 pcs
Enable, Frequency Control, Power Good
2
-
-
No
-
Buck
HIP6302
Tape & Reel (TR)
PWM Signal
-
0°C ~ 70°C (TA)
Surface Mount
16-SOIC (0.154', 3.90mm Width)
16-SOIC
Step-Down
280kHz
2
Positive
4.75V ~ 5.25V
RFQ
ISL6269ACRZ-T
Renesas Electronics America Inc
IC REG CTRLR BUCK 16QFN
En stock16472 pcs
Enable, Frequency Control, Phase Control, Power Good
1
-
Yes
No
-
Buck
ISL6269
Tape & Reel (TR)
Transistor Driver
Robust Ripple Regulator™ (R3)
-10°C ~ 100°C (TA)
Surface Mount
16-VQFN Exposed Pad
16-QFN (4x4)
Step-Down
200kHz ~ 600kHz
1
Positive
5V ~ 25V
RFQ
LTC1436AIGN-PLL#PBF
Analog Devices Inc.
IC REG CTRLR BUCK 24SSOP
En stock1930 pcs
Enable, Power on Reset, Soft Start
1
99%
Yes
No
-
Buck
LTC1436
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
24-SSOP (0.154", 3.90mm Width)
24-SSOP
Step-Down
Up to 400kHz
1
Positive
3.5V ~ 30V
RFQ
ISL8121IRZ
Renesas Electronics America Inc
IC REG CTRLR BUCK 24QFN
En stock12135 pcs
Current Limit, Enable, Soft Start, Tracking
2
66%
Yes
No
-
Buck
ISL8121
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
24-VFQFN Exposed Pad
24-QFN (4x4)
Step-Down
150kHz ~ 2MHz
2
Positive
4.9V ~ 5.5V
RFQ
ADP2323ACPZ-R7
Analog Devices Inc.
IC REG CTRLR BUCK 32LFCSP
En stock9639 pcs
Enable, Frequency Control, Power Good, Soft Start, Tracking
2
90%
No
Yes
-
Buck
ADP2323
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 125°C (TJ)
Surface Mount
32-WFQFN Exposed Pad, CSP
32-LFCSP-WQ (5x5)
Step-Down
600kHz
2
Positive
4.5V ~ 20V
RFQ
TPS40130DBTRG4
Texas Instruments
IC REG CTRLR BUCK 30TSSOP
En stock10170 pcs
Current Limit, Enable, Frequency Control, Power Good, Soft Start
2
87.5%
Yes
Yes
-
Buck
TPS40130
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
30-TFSOP (0.173', 4.40mm Width)
30-TSSOP
Step-Down
100kHz ~ 1.2MHz
2
Positive
3V ~ 40V
RFQ
5962-8670404PA
Texas Instruments
UC1845 CURRENT MODE PWM CONTROLL
En stock15480 pcs
-
-
-
-
-
-
-
5962-8670404
Bulk
-
*
-
-
-
-
-
-
-
-
-
RFQ
LTC3873ETS8-5#TRPBF
Analog Devices Inc.
IC REG CTRLR MULT TOP TSOT23-8
En stock12505 pcs
Current Limit, Enable, Soft Start
1
78%
No
No
-
Boost, Flyback, SEPIC
LTC3873
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
SOT-23-8 Thin, TSOT-23-8
TSOT-23-8
Step-Up, Step-Up/Step-Down
-
1
Positive, Isolation Capable
4.1V ~ 60V
RFQ
TPS40200MDREP
Texas Instruments
IC REG CTRLR BUCK 8SOIC
En stock12830 pcs
Frequency Control, Soft Start
1
95%
No
No
-
Buck
TPS40200
Tape & Reel (TR)
Transistor Driver
-
-55°C ~ 125°C (TJ)
Surface Mount
8-SOIC (0.154", 3.90mm Width)
8-SOIC
Step-Down
35kHz ~ 500kHz
1
Positive
4.5V ~ 52V
RFQ
LTC3854EMSE#PBF
Analog Devices Inc.
IC REG CTRLR BUCK 12MSOP
En stock15272 pcs
Enable, Soft Start
1
98%
Yes
No
-
Buck
LTC3854
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
12-TSSOP (0.118', 3.00mm Width) Exposed Pad
12-MSOP-EP
Step-Down
400kHz
1
Positive
4.5V ~ 38V
RFQ
BA9744FV-E2
Rohm Semiconductor
IC REG CTRLR BUCK/BOOST 16-SSOPB
En stock20087 pcs
Dead Time Control, Soft Start
1
100%
Yes
No
-
Buck, Boost
BA9744
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
16-LSSOP (0.173', 4.40mm Width)
16-SSOP-B
Step-Up, Step-Down
10kHz ~ 800kHz
2
Positive or Negative
2.5V ~ 35V
RFQ
TL2844DR
Texas Instruments
IC REG CTRLR BST FLYBK CM 14SOIC
En stock116960 pcs
Frequency Control
1
48%
No
No
-
Boost, Flyback, Forward
TL2844
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
14-SOIC (0.154', 3.90mm Width)
14-SOIC
Step-Up, Step-Up/Step-Down
Up to 500kHz
1
Positive
10V ~ 30V
RFQ
LTC3850IUFD#TRPBF
Analog Devices Inc.
IC REG CTRLR BUCK 28QFN
En stock10223 pcs
Current Limit, Enable, Frequency Control, Power Good, Soft Start, Tracking
2
97.2%
Yes
No
-
Buck
LTC3850
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
28-WFQFN Exposed Pad
28-QFN (4x5)
Step-Down
250kHz ~ 780kHz
2
Positive
4V ~ 30V
RFQ
UCC25705D
Texas Instruments
IC REG CTRLR MULT TOPOLOGY 8SOIC
En stock25442 pcs
Current Limit
1
93%
No
No
-
Boost, Flyback, Forward Converter
UCC25705
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
8-SOIC (0.154', 3.90mm Width)
8-SOIC
Step-Up, Step-Up/Step-Down
1MHz
1
Positive, Isolation Capable
8.2V ~ 15V
RFQ
LT1619ES8#TRPBF
Analog Devices Inc.
IC REG CTRLR MULT TOPOLOGY 8SOIC
En stock11353 pcs
Enable
1
92%
No
Yes
-
Boost, Cuk, Flyback, SEPIC
LT1619
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
8-SOIC (0.154', 3.90mm Width)
8-SO
Step-Up, Step-Up/Step-Down
300kHz
1
Positive, Isolation Capable
1.9V ~ 18V
RFQ
ISL6559CRZ
Renesas Electronics America Inc
IC REG CTRLR BUCK 32QFN
En stock16990 pcs
Current Limit, Enable, Frequency Control, Power Good
4
75%
-
No
-
Buck
ISL6559
Tube
PWM Signal
-
0°C ~ 70°C (TA)
Surface Mount
32-VFQFN Exposed Pad
32-QFN (5x5)
Step-Down
80kHz ~ 1MHz
4
Positive
4.75V ~ 5.25V
RFQ
TPS53119RGTT
Texas Instruments
DC-DC CONTROLLER
En stock13491 pcs
Enable, Soft Start
1
90%
Yes
No
-
Buck
TPS53119
Tape & Reel (TR)
Transistor Driver
D-CAP+™, Eco-Mode™
-20°C ~ 85°C (TA)
Surface Mount
16-VFQFN Exposed Pad
16-VQFN (3x3)
Step-Down
200kHz ~ 1.07MHz
1
Positive
4.5V ~ 25V
RFQ
ISL6840IBZ
Renesas Electronics America Inc
IC REG CTRLR BOOST/FLYBACK 8SOIC
En stock7730 pcs
Current Limit, Frequency Control
1
96%
Yes
No
-
Boost, Flyback
ISL6840
Tube
Transistor Driver
-
-40°C ~ 105°C (TA)
Surface Mount
8-SOIC (0.154', 3.90mm Width)
8-SOIC
Step-Up, Step-Up/Step-Down
Up to 2MHz
1
Positive, Isolation Capable
7.5V ~ 14V
RFQ
UC2844D8TR
Texas Instruments
IC PWM BOOST FLYBCK ISO CM 8SOIC
En stock66510 pcs
Frequency Control
1
48%
No
No
-
Boost, Buck, Flyback, Forward
UC2844
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
8-SOIC (0.154', 3.90mm Width)
8-SOIC
Step-Up, Step-Down, Step-Up/Step-Down
Up to 500kHz
1
Positive, Isolation Capable
12V ~ 28V
RFQ
LM25149RGYR
Texas Instruments
42-V SYNCHRONOUS BUCK DC/DC CONT
En stock16038 pcs
Current Limit, Enable, Frequency Control, Power Good, Ramp, Soft Start, Sync
1
100%
Yes
Yes
-
Buck
LM25149
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 150°C (TJ)
Surface Mount
24-VFQFN Exposed Pad
24-VQFN (5.5x3.5)
Step-Down
100kHz ~ 2.2MHz
1
Positive
3.5V ~ 42V
RFQ
NCV887801D1R2G
onsemi
IC REG CTRLR BOOST 8SOIC
En stock31346 pcs
Current Limit, Enable
1
83%
No
No
-
Boost
NCV887801
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 150°C (TJ)
Surface Mount
8-SOIC (0.154', 3.90mm Width)
8-SOIC
Step-Up
450kHz
1
Positive
2V ~ 40V
RFQ
ISL8105CRZ-T
Renesas Electronics America Inc
IC REG CTRLR BUCK 10DFN
En stock9870 pcs
Current Limit, Enable
1
100%
Yes
No
-
Buck
ISL8105
Tape & Reel (TR)
Transistor Driver
-
0°C ~ 70°C (TA)
Surface Mount
10-VFDFN Exposed Pad
10-DFN (3x3)
Step-Down
300kHz
1
Positive
6.5V ~ 14.4V
RFQ
MAX16933ATIR/V+T
Analog Devices Inc./Maxim Integrated
1MHZ, 36V, DUAL BUCK WITH 20UA Q
En stock3991 pcs
Enable, Frequency Control, Power Good
2
98.5%
Yes
Yes
-
Buck
MAX16933
Tape & Reel (TR)
Transistor Driver
Automotive, AEC-Q100
-40°C ~ 125°C (TJ)
Surface Mount
28-WFQFN Exposed Pad
28-TQFN (5x5)
Step-Down
200kHz ~ 1MHz
2
Positive
3.5V ~ 42V
RFQ
UCC38C40D
Texas Instruments
IC REG CTRLR MULT TOPOLOGY 8SOIC
En stock20683 pcs
Frequency Control
1
96%
No
No
-
Boost, Flyback, Forward Converter
UCC38C40
Tube
Transistor Driver
-
0°C ~ 70°C (TJ)
Surface Mount
8-SOIC (0.154", 3.90mm Width)
8-SOIC
Step-Up, Step-Up/Step-Down
Up to 1MHz
1
Positive
6.6V ~ 18V
RFQ
UCC2808AQDR-2G4Q1
Texas Instruments
IC REG CTRLR PUSH-PULL 8SOIC
En stock9140 pcs
Frequency Control
1
49%
No
No
-
Push-Pull
UCC2808
Bulk
Transistor Driver
Automotive, AEC-Q100
-40°C ~ 125°C (TJ)
Surface Mount
8-SOIC (0.154", 3.90mm Width)
8-SOIC
Step-Up/Step-Down
194kHz
2
Positive
4.1V ~ 15V
RFQ
NCP5212AMNTXG
onsemi
IC REG CTRLR BUCK 16QFN
En stock58740 pcs
Current Limit, Enable, Power Good
1
-
Yes
Yes
-
Buck
NCP5212
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
16-VQFN Exposed Pad
16-QFN (4x4)
Step-Down
300kHz
1
Positive
4.5V ~ 27V
RFQ
UC3879N
Texas Instruments
IC REG CTRLR HALF-BRIDGE 20DIP
En stock5508 pcs
Frequency Control, Ramp, Soft Start
1
50%
Yes
Yes
-
Half-Bridge
UC3879
Tube
Transistor Driver
-
0°C ~ 70°C (TA)
Through Hole
20-DIP (0.300', 7.62mm)
20-PDIP
Step-Up/Step-Down
Up to 300kHz
4
Positive
9V ~ 20V
RFQ
UC3844D
Texas Instruments
IC REG CTRLR PWM CM 14-SOIC
En stock53290 pcs
Frequency Control
1
48%
No
No
-
Boost, Buck, Buck-Boost, Flyback, Forward
UC3844
Tube
Transistor Driver
-
0°C ~ 70°C (TA)
Surface Mount
14-SOIC (0.154', 3.90mm Width)
14-SOIC
Step-Up, Step-Down, Step-Up/Step-Down
Up to 500kHz
1
Positive, Isolation Capable
12V ~ 28V
RFQ
LTC3828EUH#PBF
Analog Devices Inc.
IC REG CTRLR BUCK 32QFN
En stock5847 pcs
Enable, Phase Control, Power Good, Tracking
2
99.4%
Yes
No
-
Buck
LTC3828
Tube
Transistor Driver
PolyPhase®
-40°C ~ 85°C (TA)
Surface Mount
32-WFQFN Exposed Pad
32-QFN (5x5)
Step-Down
260kHz ~ 550kHz
2
Positive
4.5V ~ 28V
RFQ
LTC3808EDE#PBF
Linear Technology
LTC3808 - NO RSENSE, LOW EMI, SY
En stock6263 pcs
Enable, Frequency Control, Power Good, Soft Start, Tracking
1
100%
Yes
Yes
-
Buck
LTC3808
Bulk
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
14-WFDFN Exposed Pad
14-DFN (4x3)
Step-Down
250kHz ~ 750kHz
1
Positive
2.75V ~ 9.8V
RFQ
MIC2182-3.3YM
Microchip Technology
IC REG CTRLR BUCK 16SOIC
En stock11073 pcs
Enable, Soft Start
1
86%
Yes
Yes
-
Buck
MIC2182
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
16-SOIC (0.154", 3.90mm Width)
16-SOIC
Step-Down
300kHz
1
Positive
4.5V ~ 32V
RFQ
ISL9500CVZ-T
Renesas Electronics America Inc
IC REG CTRLR BUCK 38TSSOP
En stock12130 pcs
Enable, Frequency Control, Phase Control, Power Good
2
-
Yes
No
-
Buck
ISL9500
Tape & Reel (TR)
Transistor Driver
-
-10°C ~ 85°C (TA)
Surface Mount
38-TFSOP (0.173', 4.40mm Width)
38-TSSOP
Step-Down
250kHz ~ 1MHz
2
Positive
4.75V ~ 5.25V
RFQ
LM2747MTCX
Texas Instruments
IC REG CTRLR BUCK 14TSSOP
En stock3680 pcs
Current Limit, Enable, Frequency Control, Power Good, Soft Start, Tracking
1
86%
Yes
No
-
Buck
LM2747
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 125°C (TJ)
Surface Mount
14-TSSOP (0.173", 4.40mm Width)
14-TSSOP
Step-Down
50kHz ~ 1MHz
1
Positive
3V ~ 6V
RFQ
LT3752EFE-1#PBF
Analog Devices Inc.
IC REG CTRLR FWRD CONV 38TSSOP
En stock6402 pcs
Enable, Frequency Control, Soft Start
1
95%
Yes
Yes
-
Forward Converter
LT3752
Tube
Transistor Driver
-
-40°C ~ 125°C (TJ)
Surface Mount
38-TFSOP (0.173", 4.40mm Width) 31 Leads, Exposed Pad
38-TSSOP-EP
Step-Up/Step-Down
100kHz ~ 500kHz
1
Positive, Isolation Capable
10.5V ~ 16V
RFQ
LTC3805EDD#TRPBF
Analog Devices Inc.
IC REG CTRLR FLYBACK 10DFN
En stock18607 pcs
Enable, Soft Start
1
80%
No
Yes
-
Flyback
LTC3805
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
10-WFDFN Exposed Pad
10-DFN (3x3)
Step-Up/Step-Down
70kHz ~ 700kHz
1
Positive, Isolation Capable
3.95V ~ 9.5V
RFQ
SC1110CSTRT
Semtech Corporation
IC REG CTRLR BUCK 14SOIC
En stock13240 pcs
Current Limit, Enable, Phase Control, Soft Start
1
95%
Yes
No
-
Buck
SC1110
Tape & Reel (TR)
Transistor Driver
-
0°C ~ 70°C (TA)
Surface Mount
14-SOIC (0.154", 3.90mm Width)
14-SOIC
Step-Down
250kHz
1
Positive
4.4V ~ 12.6V
RFQ
UCC3803N
Texas Instruments
IC REG CTRLR MULT TOPOLOGY 8DIP
En stock11866 pcs
Frequency Control
1
99%
No
No
-
Buck, Boost, Flyback, Forward Converter
UCC3803
Tube
Transistor Driver
-
0°C ~ 70°C (TA)
Through Hole
8-DIP (0.300', 7.62mm)
8-PDIP
Step-Up, Step-Down, Step-Up/Step-Down
31kHz
1
Positive
3.6V ~ 12V
RFQ
LTC3855EFE#PBF
Analog Devices Inc.
IC REG CTRLR BUCK 38TSSOP
En stock5893 pcs
Current Limit, Enable, Frequency Control, Phase Control, Power Good, Soft Start, Tracking
2
95%
Yes
No
-
Buck
LTC3855
Tube
Transistor Driver
PolyPhase®
-40°C ~ 85°C (TA)
Surface Mount
38-TFSOP (0.173", 4.40mm Width) Exposed Pad
38-TSSOP-EP
Step-Down
250kHz ~ 770kHz
2
Positive
4.5V ~ 38V
RFQ
ISL6526ACB
Intersil
SWITCHING CONTROLLER
En stock70630 pcs
Enable, Phase Control
1
100%
Yes
No
-
Buck
ISL6526
Tube
Transistor Driver
-
0°C ~ 70°C (TA)
Surface Mount
14-SOIC (0.154", 3.90mm Width)
14-SOIC
Step-Down
300kHz
1
Positive
2.97V ~ 3.63V
RFQ
ISL6565BCV
Intersil
SWITCHING CONTROLLER
En stock36176 pcs
Enable, Frequency Control, Power Good
3
66.7%
-
No
-
Buck
ISL6565
Tube
PWM Signal
-
0°C ~ 105°C (TA)
Surface Mount
28-TSSOP (0.173", 4.40mm Width)
28-TSSOP
Step-Down
80kHz ~ 1.5MHz
3
Positive
4.75V ~ 5.25V
RFQ
BD9305AFVM-TR
Rohm Semiconductor
IC REG CTRLR BUCK 8MSOP
En stock31131 pcs
Enable, Frequency Control
1
100%
No
No
-
Buck
BD9305
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
8-VSSOP, 8-MSOP (0.110', 2.80mm Width)
8-MSOP
Step-Down
100kHz ~ 800kHz
1
Positive
4.2V ~ 18V
RFQ
LTC7804EUD#PBF
Analog Devices Inc.
LOW IQ SYNCHRONOUS BOOST CONTROL
En stock9966 pcs
-
1
100%
Yes
No
-
Boost
LTC7804
Tube
Transistor Driver
-
-40°C ~ 125°C (TJ)
Surface Mount
16-WFQFN Exposed Pad
16-QFN (3x3)
Step-Up
100kHz ~ 3MHz
1
Positive
4.5V ~ 40V
RFQ
LM5020MM-2
Texas Instruments
IC REG CTRLR FLYBACK 10MSOP
En stock12510 pcs
Frequency Control, Soft Start
1
50%
No
Yes
-
Flyback
LM5020
Tape & Reel (TR)
Transistor Driver
-
-40°C ~ 125°C (TJ)
Surface Mount
10-TFSOP, 10-MSOP (0.118', 3.00mm Width)
10-VSSOP
Step-Up/Step-Down
200kHz ~ 630kHz
1
Positive
8V ~ 15V
RFQ
5962-8670408XA
Texas Instruments
UC1845A CURRENT MODE PWM CONTROL
En stock942 pcs
-
-
-
-
-
-
-
5962-8670408
Bulk
-
*
-
-
-
-
-
-
-
-
-
RFQ
LTC1435IS#PBF
Analog Devices Inc.
IC REG CTRLR BUCK 16SOIC
En stock5086 pcs
Enable, Soft Start
1
99%
Yes
No
-
Buck
LTC1435
Tube
Transistor Driver
-
-40°C ~ 85°C (TA)
Surface Mount
16-SOIC (0.154', 3.90mm Width)
16-SO
Step-Down
Up to 400kHz
1
Positive
3.5V ~ 30V
RFQ