Contacto
Mapa de servicio www
Worldwide
|
Página principal
Página principal
Empresa
Nosotros
Certificados
Condiciones de venta
Cooperación de socios
Actualidades
Distribuciones
Varta Microbattery
Jamicon
SamYoung
VINATech
Pilkor
Okaya
Dongil Electronic
Prosperity Dielectrics
Walsin
HY Electronic
Cooltron
Mentor
Murrplastik
Cincon
Betterfuse
Huawei
Almacén
Contacto
Polonia
Azerbaiyán
Georgia
Ucrania
Converters
»
DC/DC Converters
Manufacturer
Bothhand (5)
Cincon (2275)
MuRata-PS (32)
UMEC/Panatel (3)
todos
Number of Outputs
1 (1565)
2 (720)
3 (30)
todos
Power
750mW (3)
1.0W (34)
1.5W (7)
1.65W (4)
2.0W (118)
2.3W (11)
3.0W (450)
3.3W (30)
4.0W (21)
5.0W (118)
5.5W (30)
5.6W (30)
5.7W (30)
6.0W (149)
6.6W (16)
7.5W (74)
8.0W (24)
8.25W (10)
9.9W (8)
10W (206)
10.8W (2)
13.2W (14)
14.4W (3)
14.85W (2)
15W (136)
16.5W (5)
18.2W (2)
19.2W (2)
19.8W (3)
20W (72)
24W (11)
24.75W (5)
25W (23)
27.2W (2)
28.8W (3)
29.4W (3)
30W (77)
33W (11)
39W (3)
39.6W (2)
40W (34)
42W (3)
43.2W (3)
49.5 (1)
49.5W (10)
50W (59)
60W (27)
66W (4)
74.88W (4)
75W (92)
82.5W (3)
99W (6)
99.6W (2)
99.9W (2)
100W (68)
100.5W (2)
100.8W (4)
115.5W (1)
125W (2)
132W (1)
150W (72)
151.2W (4)
153.6W (2)
165W (3)
198W (2)
200W (47)
231W (2)
252W (1)
299.6W (4)
300W (38)
350W (10)
400W (10)
599.2W (3)
600W (20)
602W (1)
700W (1)
750W (12)
800W (1)
todos
Series
B1 (1)
BMA1 (1)
BX2 (1)
CFB400W (10)
CFB600 (10)
CFB600-300S (3)
CFB600W-110S (8)
CFB600W-110S-CFMD (4)
CFB750-300S (6)
CFB750-300S-CMFD (6)
CFB800 (1)
CHB100 (10)
CHB100-110S (4)
CHB100W (13)
CHB150 (5)
CHB150-110S (3)
CHB150W (11)
CHB150W12 (10)
CHB150W8 (5)
CHB200 (10)
CHB200W (14)
CHB200W-110S (5)
CHB200W-110S-CMF (10)
CHB200W12 (8)
CHB300-300S (5)
CHB300-300S-CMF (10)
CHB300W (12)
CHB300W-110S (5)
CHB300W-110S-CMF (12)
CHB350 (12)
CHB50 (15)
CHB50W (14)
CHB75 (15)
CHB75D (4)
CHB75W (12)
CHE100 (2)
CHE100W (12)
CQB100-110S (4)
CQB100W (10)
CQB100W-110S (5)
CQB100W-110S-CMF (12)
CQB100W14 (12)
CQB150-300S (6)
CQB150-300S-CMF (13)
CQB150W (11)
CQB150W-110S (7)
CQB150W-110S-CMF (14)
CQB200 (4)
CQB50W12 (4)
CQB50W12-CMF (8)
CQB50W8 (5)
CQB50W8-CMF (10)
CQB60W-110S (6)
CQB75-300S (11)
CQB75-300S-CMF (10)
CQB75W (10)
CQB75W14 (12)
CQB75W8 (10)
CQB75W8-CMF (10)
CQE50W (12)
EC1SAN (19)
EC1SC (14)
EC1TAN (9)
EC2A (5)
EC2SA (28)
EC2SAN (18)
EC2SANH (18)
EC2SB (28)
EC2SBW (14)
EC2SC (18)
EC3A (112)
EC3A-E (140)
EC3AB (84)
EC3AE (50)
EC3AW (43)
EC3B (8)
EC3BB (3)
EC3C (21)
EC3SA (55)
EC3SAW (14)
EC3SAWH (14)
EC3SB (21)
EC3SBW (14)
EC3SCW (8)
EC4A (84)
EC4A-E (148)
EC4AB (84)
EC4AW (42)
EC4AW-H6 (8)
EC4BE (18)
EC4BU (28)
EC4BW (14)
EC4CE (4)
EC4EE (6)
EC4SAW (14)
EC4SAWH (14)
EC4SBW (11)
EC5A (14)
EC5B (1)
EC5BE (21)
EC5BU (21)
EC5BW (14)
EC5C (18)
EC5DAW (12)
EC5SAW (14)
EC5SBW (13)
EC6A (63)
EC6AW (28)
EC6AW-110S (5)
EC6C (27)
EC6E (16)
EC7A (63)
EC7AW (12)
EC7AW18 (6)
EC7AW18-ECRT (6)
EC7AW18-EDRT (6)
EC7B (18)
EC7BW (14)
EC7BW-110S (5)
EC7BW18 (6)
EC7BW18-ECRT (6)
EC7BW18-EDRT (6)
EC7C (36)
EC8AW (12)
EC9B (19)
EC9BW (12)
ECB40W18 (1)
ECLB40W (12)
ECLB40W-110 (7)
ECLB60 (12)
ECLB60W (12)
ECLB75W (12)
HL01U (1)
HPR1xxWC (2)
HPR4xx (1)
HUB15 (1)
LSN-10A (2)
LSN-16A (1)
LSN16A (1)
NDTS (1)
NDY (1)
NMJ (1)
NMS (1)
NMV (1)
NPH10S (1)
NPH15S (1)
NSC6 (1)
SA1-LF (1)
UCH (1)
UCQ (1)
UEI (1)
UEI15 (2)
UEI30 (4)
UHE (3)
UHP (1)
UM (1)
UM-P (2)
UST (1)
UVQ (1)
UWR (1)
todos
Output Voltage 1
1.5V (4)
1.8V (5)
2.5V (17)
3.3V (272)
5.0V (585)
9.0V (2)
12V (617)
15V (579)
24V (102)
28V (54)
32V (2)
36V (2)
48V (70)
54V (4)
todos
Output Current 1
25mA (1)
30mA (1)
33mA (3)
34mA (1)
42mA (3)
50mA (2)
60mA (2)
67mA (16)
83mA (10)
84mA (6)
100mA (81)
125mA (76)
134mA (10)
160mA (2)
167mA (10)
190mA (30)
200mA (124)
220mA (1)
230mA (31)
250mA (116)
265mA (4)
300mA (67)
300mAh (1)
310mA (12)
333mA (38)
400mA (66)
415mA (5)
416mA (22)
417mA (9)
470mA (31)
500mA (112)
530mA (4)
600mA (136)
625mA (32)
660mA (2)
666mA (41)
667mA (4)
668mA (3)
670mA (3)
700mA (11)
750mA (9)
800mA (4)
830mA (7)
833mA (25)
835mA (18)
1.0A (141)
1.04A (4)
1.05A (5)
1.2A (26)
1.25A (32)
1.3A (1)
1.33A (12)
1.333A (3)
1.4A (5)
1.5A (51)
1.56A (12)
1.6A (11)
1.667A (3)
1.67A (12)
1.78A (2)
1.79A (3)
1.8A (3)
1.85A (2)
2.0A (76)
2.08A (13)
2.1A (9)
2.14A (1)
2.5A (34)
2.666A (6)
2.67A (4)
2.7A (2)
3.0A (58)
3.12A (16)
3.13A (4)
3.2A (11)
3.3A (3)
3.33A (8)
3.333A (7)
3.5A (6)
3.6A (5)
4.0A (32)
4.16A (7)
4.17A (11)
4.20A (2)
4.2A (19)
4.5A (2)
5.0A (39)
5.35A (1)
5.4A (9)
5.5A (2)
6.0A (33)
6.25A (29)
6.3A (11)
6.5A (3)
6.7A (13)
7.14A (7)
7.3A (2)
7.5A (9)
8.0A (12)
8.3A (18)
8.33A (2)
8.4A (9)
9.0A (1)
10A (41)
10.7A (8)
12A (10)
12.5A (32)
13.3A (2)
13.5A (2)
14.3A (2)
14.6A (2)
15A (28)
15.6A (2)
16A (2)
16.7A (11)
19A (2)
20A (21)
20.8A (2)
21A (1)
21.4A (3)
21.5A (1)
25A (20)
26.7A (2)
28.5A (1)
29.2A (2)
30A (20)
31.2A (2)
33.3A (2)
35A (1)
40A (8)
50A (11)
60A (10)
62.5A (2)
70A (4)
80A (2)
todos
Input Voltage
3.0V ~ 3.6V (1)
3.0V ~ 5.5V (2)
4.5V ~ 5.25V (1)
4.5V ~ 5.5V (45)
4.5V ~ 6.0V (28)
4.5V ~ 9.0V (56)
4.7V ~ 6.0V (2)
4.7V ~ 9.0V (14)
8.5V ~ 160V (13)
9.0V ~ 18V (362)
9.0V ~ 32V (8)
9.0V ~ 36V (286)
9.0V ~ 75V (40)
10V ~ 160V (24)
10V ~ 36V (7)
10.8V ~ 13.2V (33)
12V ~ 160V (24)
14V ~ 160V (30)
16V ~ 32V (2)
16.8V ~ 33V (1)
18V ~ 36V (408)
18V ~ 72V (81)
18V ~ 74V (26)
18V ~ 75V (184)
19V ~ 32V (2)
21.6V ~ 26.4V (33)
23.3V ~ 30V (1)
25.2V ~ 30.8V (10)
36V ~ 72V (253)
36V ~ 75V (142)
43V ~ 160V (105)
43.2V ~ 52.8V (10)
66V ~ 160V (11)
180V ~ 425V (37)
180V ~ 450V (21)
200V ~ 425V (12)
todos
Isolation Voltage
500VDC (585)
750VDC (2)
1000VDC (32)
1500VDC (1042)
2000VDC (2)
2250VDC (56)
3000VAC (187)
3000VDC (379)
4000VDC (1)
4200VDC (1)
5200VDC (1)
6000VDC (9)
todos
Output Voltage 2
-24V (6)
-15V (251)
-12V (257)
-5.0V (198)
2.5V (2)
3.3V (2)
5.0V (3)
12V (17)
15V (13)
todos
Output Current 2
25mA (1)
30mA (1)
33mA (3)
34mA (1)
42mA (3)
50mA (1)
60mA (2)
67mA (8)
83mA (11)
100mA (81)
125mA (76)
190mA (30)
200mA (39)
230mA (31)
250mA (43)
265mA (4)
300mA (72)
310mA (18)
333mA (37)
400mA (6)
415mA (5)
416mA (22)
417mA (9)
500mA (74)
600mA (6)
625mA (25)
660mA (2)
666mA (4)
667mA (4)
670mA (3)
678mA (1)
750mA (9)
800mA (4)
830mA (2)
833mA (7)
835mA (5)
1.0A (35)
1.25A (12)
1.333A (3)
1.40A (3)
1.5A (16)
1.56A (2)
1.667A (3)
1.80A (3)
2.0A (6)
2.5A (7)
3.12A (2)
7.5A (3)
15A (4)
todos
Output Voltage 3
-15V (13)
-12V (13)
-5.0V (4)
todos
Output Current 3
250mA (5)
300mA (6)
310mA (4)
400mA (6)
500mA (4)
625mA (3)
1.0A (2)
todos
Efficiency
50% (6)
57% (1)
60% (1)
61% (49)
65% (1)
67% (1)
68% (5)
70% (11)
71% (8)
71.5% (1)
72% (43)
73% (11)
74% (24)
75% (13)
76% (61)
77% (93)
78% (70)
79% (95)
79.5% (1)
80% (137)
80.5% (4)
81% (145)
81.5% (2)
82% (128)
82.5% (4)
83% (111)
83.5% (2)
84% (106)
84.5% (3)
85% (129)
85.5% (7)
86% (110)
86.5% (9)
87% (192)
87.3% (1)
87.5% (20)
88% (175)
88.5% (36)
89% (128)
89.5% (30)
90% (151)
90.5% (40)
91% (68)
91.5% (19)
92% (34)
92.5% (9)
92.6% (1)
93% (9)
93.5% (2)
94% (2)
todos
Ripple/Noise
10mV p-p (2)
30mV p-p (3)
40mV p-p (2)
50mV p-p (144)
60mV p-p (7)
70mV p-p (2)
75mV p-p (414)
100mV p-p (814)
120mV p-p (57)
125mV p-p (1)
150mV p-p (159)
165mV p-p (1)
200mV p-p (56)
240mV p-p (84)
280mV p-p (39)
300mV p-p (17)
320mV p-p (2)
480mV p-p (52)
600mV p-p (4)
650mV p-p (2)
750mV p-p (2)
1% p-p (428)
todos
Type
Isolated (2296)
Non-isolated (18)
todos
Package/Case
A (metal) (329)
A (plastic) (360)
AS (metal) (223)
AS (plastic) (91)
B (214)
C (106)
C32 (3)
C4 (1)
C74 (1)
C75 (2)
C80 (4)
DIP (2)
DIP-24 (5)
E (22)
FB (48)
HB (240)
LB (55)
PDIP-16 (12)
QB (207)
SB (101)
SC (40)
SIL-7 (3)
SIP (4)
SIP-11 (vertical) (3)
SIP-11 horizontal (1)
SIP-4 (8)
SIP-6 (1)
SIP-7 (57)
SIP-8 (153)
SMD (1)
50.8x25.4x12.7 (1)
todos
Mounting Style
- (30)
SMD (316)
THT (1969)
todos
Remote On/Off Logic
dodatnie (opcja) (58)
negative (147)
positive (1064)
todos
Industry
Railway System (276)
todos
Tₘᵢₙ
-40°C (1622)
-25°C (692)
0°C (1)
todos
Tₘₐₓ
60°C (1)
70°C (2)
71°C (703)
75°C (1)
80°C (18)
85°C (1033)
100°C (388)
105°C (167)
110°C (2)
todos
Packaging
Antistatic Foam (437)
Bag (10)
Inner Box (70)
Tray (5)
Tube (1700)
woreczek bąbelkowy (77)
todos
Número de posiciones en la página
10
25
50
100
Partidas
401
a
425
de
2315
<<
-10
<
12
13
14
15
16
17
18
19
20
21
22
>
+10
>>
Designación del fabricante
Fabricante
Índice Ropla
Number of Outputs
Power
Series
Output Voltage 1
Output Current 1
Input Voltage
Isolation Voltage
Output Voltage 2
Output Current 2
Output Voltage 3
Output Current 3
Efficiency
Ripple/Noise
Type
Package/Case
Mounting Style
Remote On/Off Logic
Industry
Tₘᵢₙ
Tₘₐₓ
Packaging
Estado
Precio neto
MOQ
Multiple
401
EC2SB-48S15
Cincon
1
10W
EC2SB
15V
666mA
36V ~ 75V
1500VDC
87%
50mV p-p
Isolated
SB
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1124
10W 15V/666mA Isolated DC/DC Converter, 36-75Vin, n=87%, Viso=1500VDC
402
EC2SBW-24S15
Cincon
1
10W
EC2SBW
15V
666mA
9.0V ~ 36V
1500VDC
86%
100mV p-p
Isolated
SB
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1131
10W 15V/666mA Isolated DC/DC Converter, 9-36Vin, n=86%, Viso=1500VDC
403
EC2SBW-48S15
Cincon
1
10W
EC2SBW
15V
666mA
18V ~ 75V
1500VDC
86%
100mV p-p
Isolated
SB
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1138
10W 15V/666mA Isolated DC/DC Converter, 18-75Vin, n=86%, Viso=1500VDC
404
EC4BE03
Cincon
1
10W
EC4BE
15V
666mA
9.0V ~ 18V
500VDC
78%
100mV p-p
Isolated
B
THT
-25°C
71°C
Tube
0 pcs
on stock
ya no se fabrica
1
1
CIN0790
10W 15V/666mA Isolated DC/DC Converter, 9-18Vin, n=78%, Viso=500VDC
405
EC4BE13
Cincon
1
10W
EC4BE
15V
666mA
18V ~ 36V
500VDC
80%
100mV p-p
Isolated
B
THT
-25°C
71°C
Tube
4 pcs
on stock
ya no se fabrica
1
1
CIN0064
10W 15V/666mA Isolated DC/DC Converter, 18-36Vin, n=80%, Viso=500VDC
406
EC4BE23
Cincon
1
10W
EC4BE
15V
666mA
36V ~ 72V
500VDC
82%
100mV p-p
Isolated
B
THT
-25°C
71°C
Tube
0 pcs
on stock
ya no se fabrica
1
1
CIN0795
10W 15V/666mA Isolated DC/DC Converter, 36-72Vin, n=82%, Viso=500VDC
407
EC4BU-05S15
Cincon
1
10W
EC4BU
15V
666mA
4.7V ~ 9.0V
1500VDC
87%
100mV p-p
Isolated
B
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN0202
10W 15V/666mA Isolated DC/DC Converter, 4.7-9Vin, n=87%, Viso=1500VDC
408
EC4BU-12S15
Cincon
1
10W
EC4BU
15V
666mA
9.0V ~ 18V
1500VDC
87%
100mV p-p
Isolated
B
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN0184
10W 15V/666mA Isolated DC/DC Converter, 9-18Vin, n=87%, Viso=1500VDC
409
EC4BU-24S15
Cincon
1
10W
EC4BU
15V
666mA
18V ~ 36V
1500VDC
87%
100mV p-p
Isolated
B
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN0503
10W 15V/666mA Isolated DC/DC Converter, 18-36Vin, n=87%, Viso=1500VDC
410
EC4BU-48S15
Cincon
1
10W
EC4BU
15V
666mA
36V ~ 75V
1500VDC
87%
100mV p-p
Isolated
B
THT
positive
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN0196
10W 15V/666mA Isolated DC/DC Converter, 36-75Vin, n=87%, Viso=1500VDC
411
EC4BW03
Cincon
1
10W
EC4BW
15V
666mA
9.0V ~ 36V
500VDC
80%
75mV p-p
Isolated
B
THT
-25°C
71°C
Tube
0 pcs
on stock
1
1
CIN0208
10W 15V/666mA Isolated DC/DC Converter, 9-36Vin, n=80%, Viso=500VDC
412
EC4BW13
Cincon
1
10W
EC4BW
15V
666mA
18V ~ 72V
500VDC
81%
75mV p-p
Isolated
B
THT
-25°C
71°C
Tube
0 pcs
on stock
1
1
CIN0215
10W 15V/666mA Isolated DC/DC Converter, 18-72Vin, n=81%, Viso=500VDC
413
EC5A-12S15
Cincon
1
10W
EC5A
15V
666mA
9.0V ~ 32V
87%
1% p-p
Non-isolated
A (metal)
THT
-25°C
71°C
Tube
0 pcs
on stock
1
1
CIN1764
10W 15V/666mA Non-Isolated DC/DC Converter, 9-32Vin, n=87%
414
EC5A-12S15S
Cincon
1
10W
EC5A
15V
666mA
9.0V ~ 32V
87%
1% p-p
Non-isolated
AS (metal)
SMD
-25°C
71°C
Tube
0 pcs
on stock
1
1
CIN1771
10W 15V/666mA Non-Isolated DC/DC Converter, 9-32Vin, n=87%
415
EC5DAW-24S15N
Cincon
1
10W
EC5DAW
15V
666mA
9.0V ~ 36V
3000VDC
89%
150mV p-p
Isolated
PDIP-16
THT
negative
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN3069
10W 15V/666mA Isolated DC/DC Converter, 9-36Vin, n=89%, Viso=3000VDC
416
EC5DAW-48S15N
Cincon
1
10W
EC5DAW
15V
666mA
18V ~ 74V
3000VDC
88%
120mV p-p
Isolated
PDIP-16
THT
negative
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN3075
10W 15V/666mA Isolated DC/DC Converter, 18-74Vin, n=88%, Viso=3000VDC
417
EC5SAW-24S15N
Cincon
1
10W
EC5SAW
15V
666mA
9.0V ~ 36V
3000VDC
89.5%
1% p-p
Isolated
SIP-8
THT
negative
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN2185
10W 15V/666mA Isolated DC/DC Converter, 9-36Vin, n=89.5%, Viso=3000VDC
418
EC5SAW-48S15N
Cincon
1
10W
EC5SAW
15V
666mA
18V ~ 75V
3000VDC
88%
1% p-p
Isolated
SIP-8
THT
negative
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN2192
10W 15V/666mA Isolated DC/DC Converter, 18-75Vin, n=88%, Viso=3000VDC
419
EC6AW-110S15
Cincon
1
10W
EC6AW-110S
15V
666mA
43V ~ 160V
3000VDC
88.5%
100mV p-p
Isolated
A (plastic)
THT
positive
Railway System
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1198
10W 15V/666mA Isolated DC/DC Converter, 43-160Vin, n=88.5%, Viso=3000VDC, UL
420
EC7A-12S15
Cincon
1
10W
EC7A
15V
666mA
9.0V ~ 18V
1500VDC
88%
75mV p-p
Isolated
A (metal)
THT
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN0860
10W 15V/666mA Isolated DC/DC Converter, 9-18Vin, n=88%, Viso=1500VDC
421
EC7A-12S15
Cincon
1
10W
EC7A
15V
666mA
9.0V ~ 18V
1500VDC
88%
75mV p-p
Isolated
A (metal)
THT
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1951
10W 15V/666mA Isolated DC/DC Converter, 9-18Vin, n=88%, Viso=1500VDC, UL
422
EC7A-12S15S
Cincon
1
10W
EC7A
15V
666mA
9.0V ~ 18V
1500VDC
88%
75mV p-p
Isolated
AS (metal)
SMD
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1799
10W 15V/666mA Isolated DC/DC Converter, 9-18Vin, n=88%, Viso=1500VDC
423
EC7A-24S15
Cincon
1
10W
EC7A
15V
666mA
18V ~ 36V
1500VDC
88%
75mV p-p
Isolated
A (metal)
THT
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1958
10W 15V/666mA Isolated DC/DC Converter, 18-36Vin, n=88%, Viso=1500VDC, UL
424
EC7A-24S15
Cincon
1
10W
EC7A
15V
666mA
18V ~ 36V
1500VDC
88%
75mV p-p
Isolated
A (metal)
THT
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN0866
10W 15V/666mA Isolated DC/DC Converter, 18-36Vin, n=88%, Viso=1500VDC
425
EC7A-24S15S
Cincon
1
10W
EC7A
15V
666mA
18V ~ 36V
1500VDC
88%
75mV p-p
Isolated
AS (metal)
SMD
-40°C
85°C
Tube
0 pcs
on stock
1
1
CIN1806
10W 15V/666mA Isolated DC/DC Converter, 18-36Vin, n=88%, Viso=1500VDC
Número de posiciones en la página
10
25
50
100
Partidas
401
a
425
de
2315
<<
-10
<
12
13
14
15
16
17
18
19
20
21
22
>
+10
>>
Busca
Estado
todos
>= 1
>= 10
>= 100
>= 1000
>= 10000
>= 100000
Antennas
Batteries & Rechargeable Cells
Capacitors
Converters
DC/DC Converters
Electrotechnics Components
EMI Components
Inductors, Chokes & Coils
Optoelectronics Components
Power Supplies and Chargers
Quartz and filters
Resistors
Semiconductors
Sensors
Surge Protection