Re: Drat. NTE is gone, and they took the last 5-GHz PNP with them.

On 2024-09-09 21:59, Phil Hobbs wrote:

On 2024-09-04 17:54, Phil Hobbs wrote:

The NTE2403, similar to the BFT92, but a bit better overall.  Dunno who actually made them. (I saw the news on s.e.repair today.)
>
Rochester claims to have 1,500,000 of the 2SA1462 (1.8 GHz) for 20 cents, but that's all she wrote.
>
I have a couple of reels of BFT92s and one of BFG31s, so I'm good for protos and small production, but I can't use PNP wraparound bootstraps for customer designs anymore. :(
>
Barstids.

>

Something like this. This is what I call a Type 2 bootstrap, in which the bootstrap device is inside the TIA feedback loop.  You have to worry about drift and 1/f noise in the FET, but that's usually the least of your worries.

Wrong file--this should be the right one
  ===========Version 4
SHEET 1 2276 1012
WIRE -496 112 -656 112
WIRE -464 112 -496 112
WIRE -224 112 -240 112
WIRE -112 112 -128 112
WIRE -224 128 -224 112
WIRE -128 128 -128 112
WIRE -496 144 -496 112
WIRE -656 192 -656 112
WIRE -224 224 -224 208
WIRE -128 224 -128 208
WIRE -496 240 -496 224
WIRE -496 240 -592 240
WIRE 160 240 112 240
WIRE 288 240 224 240
WIRE -496 256 -496 240
WIRE -656 320 -656 288
WIRE -288 320 -448 320
WIRE -192 320 -288 320
WIRE 112 320 112 240
WIRE 112 320 -192 320
WIRE 160 320 112 320
WIRE 288 320 288 240
WIRE 288 320 240 320
WIRE -288 336 -288 320
WIRE -192 368 -192 320
WIRE 288 432 288 320
WIRE -656 480 -656 400
WIRE -496 480 -496 352
WIRE -496 480 -656 480
WIRE -368 480 -496 480
WIRE -288 480 -288 416
WIRE -288 480 -368 480
WIRE -192 480 -192 432
WIRE -192 480 -288 480
WIRE -48 480 -192 480
WIRE 160 480 32 480
WIRE 288 496 288 432
WIRE 288 496 224 496
WIRE 160 512 128 512
WIRE -368 528 -368 480
WIRE 128 544 128 512
WIRE -672 576 -704 576
WIRE -560 576 -592 576
WIRE -496 576 -560 576
WIRE -432 576 -496 576
WIRE -704 592 -704 576
WIRE -496 592 -496 576
WIRE -560 608 -560 576
WIRE -368 640 -368 624
WIRE -560 736 -560 672
WIRE -560 736 -576 736
WIRE -496 736 -496 672
WIRE -496 736 -560 736
WIRE -368 736 -368 720
WIRE -368 736 -496 736
FLAG -128 224 0
FLAG -224 224 0
FLAG -240 112 VCC
FLAG -112 112 VEE
FLAG -576 736 VEE
FLAG -464 112 VCC
FLAG 192 464 VCC
FLAG 192 528 VEE
FLAG 128 544 0
FLAG 288 432 out
FLAG -704 592 0
SYMBOL voltage -128 112 R0
WINDOW 0 41 50 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value -5
SYMBOL voltage -224 112 R0
WINDOW 0 -69 56 Left 2
SYMATTR InstName V2
SYMATTR Value +5
SYMBOL njf -448 256 M0
WINDOW 3 -112 -9 Left 2
SYMATTR Value BF862_1pA
SYMATTR InstName J1
SYMBOL res -512 128 R0
SYMATTR InstName R5
SYMATTR Value 100
SYMBOL pnp -592 288 R180
SYMATTR InstName Q2
SYMATTR Value BFT92
SYMBOL current -288 336 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
WINDOW 3 -58 -60 Left 2
SYMATTR InstName I1
SYMATTR Value PULSE(1u 1n 10n 10n 10n 0.5u)
SYMBOL res 144 336 R270
WINDOW 0 32 64 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R4
SYMATTR Value 1Meg
SYMBOL cap 160 256 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName C3
SYMATTR Value 0.1p
SYMBOL cap -208 368 R0
SYMATTR InstName C4
SYMATTR Value 100p
SYMBOL res 48 464 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName Rsense2
SYMATTR Value 1m
SYMBOL res -640 304 M0
SYMATTR InstName Rsense1
SYMATTR Value 1m
SYMBOL npn -432 528 R0
SYMATTR InstName Q1
SYMATTR Value BFU520D
SYMBOL res -384 624 R0
SYMATTR InstName R2
SYMATTR Value 160
SYMBOL res -512 576 R0
SYMATTR InstName R7
SYMATTR Value 1k
SYMBOL res -576 560 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL cap -576 608 R0
SYMATTR InstName C1
SYMATTR Value 1u
SYMBOL OpAmps\UniversalOpAmp2 192 496 R0
WINDOW 123 -101 86 Left 2
WINDOW 39 -97 152 Left 2
WINDOW 40 -106 117 Left 2
SYMATTR InstName U1
SYMATTR Value2 Avol=50k GBW=120Meg Slew=3G
SYMATTR SpiceLine Ilimit=50m Rail=0 Vos=0
SYMATTR SpiceLine2 En=12n Enk=0 In=0 Ink=0 Rin=500Meg
TEXT -808 688 Left 2 !.tran 1.5u
TEXT -104 344 Left 3 ;Photodiode
TEXT 248 520 Left 2 ;Similar to \nLM6171
TEXT 408 432 Left 2 !.model BF862_1pA NJF(Beta=47.800E-3 Betatce=-.5 Rd=.8 Rs=7.5000 Lambda=37.300E-3 Vto=-.57093\n+ Vtotc=-2.0000E-3 Is=6e-15 Isr=6e-15 N=1 Nr=2 Xti=3 Alpha=-1.0000E-3\n+ Vk=59.97 Cgd=7.4002E-12 M=.6015 Pb=.5 Fc=.5 Cgs=8.2890E-12 Kf=87.5E-18\n+ Af=1)
TEXT 400 288 Left 2 !.MODEL BFU520D NPN( IS = 71.49E-18 BF = 133.81 NF = 1.00 VAF = 183.69 IKF = 252.72E-3 ISE = 89.40E-15\n+NE = 2.50 BR = 512.49E-3 NR = 1.00 VAR = 2.40 IKR = 31.59E-3 ISC = 71.49E-18 NC = 1.10\n+RB = 1.17 IRB = 26.78E-3 RBM = 0.67 RE = 0.59 RC = 0.89 CJE = 506.04E-15 VJE = 950.00E-3\n+MJE = 335.33E-3 CJC = 74.16E-15 VJC = 720.00E-3 MJC = 318.44E-3 XCJC = 0.50 FC = 850.00E-3 TF = 10.04E-12\n+XTF = 10.00 VTF = 1.00 ITF = 42.55E-3 PTF = 0.00 TR = 0.00 KF = 109.67e-12 AF = 2.00)
TEXT 616 528 Left 2 !.MODEL  BFT92   PNP(  IS = 4.3756E-016 BF = 33.5815 NF = 1.0097 VAF = 23.3946\n+    IKF = 9.9538E-002 ISE = 8.7054E-014 NE = 1.94395 BR = 4.9472\n+    NR = 1.00254 VAR = 3.90385 IKR = 5.2816E-003 ISC = 3.5886E-014\n+    NC = 1.3933 RB = 5 IRB = 1E-006 RBM = 5 RE = 1 RC = 10 EG = 1.11\n+    XTI = 3 CJE = 7.4666E-013 VJE = .6 MJE = .35683 TF = 1.7492E-011\n+    XTF = 1.3546 VTF = .155654 ITF = 1E-003 PTF = 45 CJC = 9.371E-013\n+    VJC = .396455 MJC = .19995 XCJC = .106 TR = 8.422E-009\n+    VJS = .75 FC = .767856)
TEXT 352 96 Left 3 ;PNP WRAPAROUND BOOTSTRAP\nType 2: Bootstrap inside TIA loop, A_V = 0.993, 154 ns t_R\n \nPhil Hobbs\nElectroOptical Innovations LLC
RECTANGLE Normal 48 528 -352 256 2
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com