2N4856A/4857A/4858A
Vishay Siliconix
Document Number: 70243
S-04028—Rev. D, 04-Jun-01 www.vishay.com
7-1
N-Channel JFETs
PRODUCT SUMMARY
Part
Number VGS(off)
(V) V(BR)GSS
Min (V) IDSS Min
(mA) rDS(on) Max
(W)ID(off) Typ
(pA) tON Typ
(ns)
2N4856A –4 to –10 –40 50 25 5 4
2N4857A –2 to –6 –40 20 40 5 4
2N4858A –0.8 to –4 –40 8 60 5 4
FEATURES BENEFITS APPLICATIONS
DLow On-Resistance: 2N4856A
<25 W
DFast Switching—tON: 4 ns
DHigh Off-Isolation—ID(off): 5 pA
DLow Capacitance: 3 pF
DLow Insertion Loss
DLow Error Voltage
DHigh-Speed Analog Circuit Performance
DNegligible “Off-Error,” Excellent Accuracy
DGood Frequency Response
DEliminates Additional Buffering
DAnalog Switches
DChoppers
DSample-and-Hold
DNormally “On” Switches
DCurrent Limiters
DESCRIPTION
The 2N4856A/4857A/4858A all-purpose JFET analog
switches offer low on-resistance, low capacitance, good
isolation, and fast switching.
Hermetically-sealed TO-206AA (T O-18) packaging allows full
military processing (see Military Information). For similar
products i n T O-226AA (TO-92) and SOT-23 packages, see the
J/SST111 series data sheet. For similar duals, see the
2N5564/5565/5566 data sheet.
D
S
G and Case
TO-206AA
(TO-18)
Top View
1
23
2N4856A/4857A/4858A
Vishay Siliconix
www.vishay.com
7-2 Document Number: 70243
S-04028—Rev. D, 04-Jun-01
ABSOLUTE MAXIMUM RATINGS
Gate-Drain, Gate-Source Voltage : (2N4856A-58A) –40 V. . . . . . . . . . . . . . .
Gate Current 50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead Temperature (1/16” from case for 10 seconds) 300 _C. . . . . . . . . . . . . .
Storage Temperature –65 to 200_C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Junction Temperature –55 to 200_C. . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipationa1.8 W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Notes
a. Derate 1 0 m W / _C for TC > 25_C
SPECIFICATIONS (TA = 25_C UNLESS OTHERWISE NOTED)
Limits
2N4856A 2N4857A 2N4858A
Parameter Symbol Test Conditions TypaMin Max Min Max Min Max Unit
Static
Gate-Source
Breakdown Voltage V(BR)GSS IG = –1 mA , VDS = 0 V –55 –40 –40 –40 V
Gate-Source Cutoff Voltage VGS(off) VDS = 15 V, ID = 0.5 nA –4–10 –2–6–0.8 –4V
Saturation Drain CurrentbIDSS VDS = 15 V, VGS = 0 V 50 20 100 8 80 mA
VGS = –20 V, VDS = 0 V –5–250 –250 –250 pA
Gate Reverse Current IGSS TA = 150_C–13 –500 –500 –500 nA
Gate Operating CurrentcIGVDG = 15 V, ID = 10 mA –5
VDS = 15 V, VGS = –10 V 5 250 250 250 pA
Drain Cutoff Current ID(off) TA = 150_C13 500 500 500 nA
ID = 5 mA 0.25 0.5
Drain-Source On-Voltage VDS(on) VGS = 0 V ID = 10 mA 0.35 0.5 V
ID = 20 mA 0.5 0.75
Drain-Source On-ResistancecrDS(on) VGS = 0 V, ID = 1 mA 25 40 60 W
Gate-Source Forward VoltagecVGS(F) IG = 1 mA , VDS = 0 V 0.7 V
Dynamic
Common-Source
Forward T ransconductancecgfs VDS = 20 V, ID = 1 mA 6 mS
Common-Source
Output Conductancecgos
VDS = 20 V, ID = 1 mA
f = 1 kHz 25 mS
Drain-Source On-Resistance rds(on) VGS = 0 V, ID = 0 mA
f = 1 kHz 25 40 60 W
Common-Source
Input Capacitance Ciss VDS = 0 V, VGS = –10 V 7 10 10 10
Common-Source
Reverse Transfer Capacitance Crss
VDS = 0 V, VGS = –10 V
f = 1 MHz 3 4 3.5 3.5 pF
Equivalent Input
Noise VoltagecenVDS = 10 V, ID = 10 mA
f = 1 kHz 3nV⁄
√Hz
Switching
td(on) 2 5 6 8
T urn-On Time trVDD = 10 V, VGSH = 0 V
See Switching Circuit 2 3 4 8 ns
Turn-Off Time tOFF
See Switching Circuit 12 20 40 80
Notes
a. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing. NCB
b. Pulse test: PW v100 ms duty cycle v10%.
c. This parameter not registered with JEDEC.
2N4856A/4857A/4858A
Vishay Siliconix
Document Number: 70243
S-04028—Rev. D, 04-Jun-01 www.vishay.com
7-3
TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED)
160
120
On-Resistance and Drain Current
vs. Gate-Source Cutoff Voltage On-Resistance vs. Drain Current
100
0–10
0
200
160
0
rDS IDSS
rDS @ ID = 1 mA, VGS = 0
IDSS @ VDS = 20 V, VGS = 0
100
0
1 10 100
VGS(off) = –2 V
–4 V
–8 V
TA = 25_C
On-Resistance vs. Temperature
200
–55 25 125
0–15 85
ID = 1 mA
rDS changes X 0.7%/_C
VGS(off) = –2 V
–4 V
–8 V
Turn-On Switching
5
0–10
4
3
2
1
0
tr
Switching T ime (ns)
td(on) @
ID = 3 mA
td(on) @
ID = 12 mA
tr approximately independent of ID
VDG = 5 V, RG = 50 W
VGS(L) = –10 V
Turn-Off Switching
30
010
24
18
12
6
0
VGS(off) = –2 V
VGS(off) = –8 V
td(off)
td(off) independent of device VGS(off)
VDG = 5 V, VGS(L) = –10 V
Capacitance vs. Gate-Source Voltage
30
–20
24
18
12
6
Capacitance (pF)
f = 1 MHz
0
VGS(off) – Gate-Source Cutoff Voltage (V)
TA – Temperature (_C)
VGS – Gate-Source Voltage (V)
VGS(off) – Gate-Source Cutoff Voltage (V)
ID – Drain Current (mA)
ID – Drain Current (mA)
80
60
40
20
80
40
80
60
40
20
–2–4–6–8
–35
120
80
40
5 45 65 105 –2–4–6–8
2468 –4–8–12 –16
Switching T ime (ns)
0
tf
rDS(on) – Drain-Source On-Resistance ( Ω )
IDSS – Saturation Drain Current (mA)
rDS(on) – Drain-Source On-Resistance ( Ω )
rDS(on) – Drain-Source On-Resistance ( Ω )
Ciss @ VDS = 0 V
Crss @ VDS = 0 V
2N4856A/4857A/4858A
Vishay Siliconix
www.vishay.com
7-4 Document Number: 70243
S-04028—Rev. D, 04-Jun-01
TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED)
1 pA
Noise Voltage vs. Frequency
100
10
110 100 1 k 100 k10 k
ID = 1 mA
ID = 10 mA
VDG = 10 V
Forward Transconductance and Output Conductance
vs. Gate-Source Cutoff Voltage
50
0
0–2–10
500
300
0
gfs gos
gfs and gos @ VDS = 20 V
VGS = 0 V, f = kHz
Gate Leakage Current
030
1 nA
100 pA
10 pA
0.1 pA
TA = 125_C
TA = 25_C
1 mA
IGSS @ 25_C
10 nA
ID = 10 mA
Common-Gate Input Admittance
100
10
1
0.1100 1000200 500
(mS)
gig
big
VDG = 10 V
ID = 10 mA
TA = 25_C
Common-Gate Forward Admittance Common-Gate Reverse Admittance
100
10
1
0.1100 1000200 500
(mS)
–gfg bfg
gfg
VDG = 10 V
ID = 10 mA
TA = 25_C
10
1
0.1
0.01100 1000200 500
VDG = 10 V
ID = 10 mA
TA = 25_C
–grg
–brg
+grg
(mS)
VDG – Drain-Gate Voltage (V)
VGS(off) – Gate-Source Cutoff Voltage (V)f – Frequency (Hz)
f – Frequency (MHz)
f – Frequency (MHz) f – Frequency (MHz)
40
30
20
10
–4–6–8
IGSS @ 25_C
10 mA
1 mA
6 121824
400
100
200
IG(on) @ ID
en – Noise Voltage nV / Hz
gos – Output Conductance (µS)
gfs – Forward Transconductance (mS)
IG – Gate Leakage
51 Ω
51 Ω
1 κΩ
VIN
Scope
VDD
RL
OUT
VGS(H)
VGS(L)
2N4856A/4857A/4858A
Vishay Siliconix
Document Number: 70243
S-04028—Rev. D, 04-Jun-01 www.vishay.com
7-5
TYPICAL CHARACTERISTICS (TA = 25_C UNLESS OTHERWISE NOTED)
Common-Gate Output Admittance
100
10
1
0.1100 1000200 500
(mS)
gog
bog
VDG = 10 V
ID = 10 mA
TA = 25_C
f – Frequency (MHz)
20
0 1.0
16
12
8
4
0
VDS – Drain-Source Voltage (V)
0.2 0.4 0.6 0.8
VGS = 0 V
Output Characteristics
–0.2 V
–0.4 V
–0.6 V
–0.8 V
–1.2 V
–1.0 V
40
0 1.0
32
24
16
8
0
VDS – Drain-Source Voltage (V)
0.2 0.4 0.6 0.8
VGS = 0 V
Output Characteristics
–0.5 V
–1.0 V
–1.5 V
–2.0 V
–3.0 V
–2.5 V
50
0 1.0
40
30
20
10
0
VDS – Drain-Source Voltage (V)
0.2 0.4 0.6 0.8
VGS = 0 V
Output Characteristics
–1 V
–3 V
–4 V
–2 V
–6 V
–5 V
VGS(off) = –2 V
VGS(off) = –4 V VGS(off) = –8 V
ID – Drain Current (mA)
ID – Drain Current (mA) ID – Drain Current (mA)
SWITCHING TIME TEST CIRCUIT
2N4856A 2N4857A 2N4858A
VGS(L) –10 V –6 V –4 V
RL*464 W953 W1910 W
ID(on) 20 mA 10 mA 5 mA
*Non-inductive
INPUT PULSE SAMPLING SCOPE
Rise Time < 1 ns
Fall Time < 1 ns
Pulse Width 100 ns
PRF 1 MHz
Rise Time 0.4 ns
Input Resistance 10 MW
Input Capacitance 1.5 pF
Document Number: 91000 www.vishay.com
Revision: 18-Jul-08 1
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