BL431 ADJUSTABLE PRECISION ZENER SHUNT REGULATOR BL431 DESCRIPTION Ou tline Dra win g The B L4 31 is a th ree -termin al ad justab le reg u la to r with a gu a ra nteed th erma l stab ility o ve r app lic ab le te mp era tu re ra nge s. T he ou tpu t vo ltag e ma y be set to an y va lu e b e twee n VREF (ap prox ima te ly 2 .5V) and 36V with two ex tern a l re sisto rs. Th is de vice has typ ica l d yn a mic o utp u t imped an ce o f 0.2 Ω . Active ou tp ut c irc uitry SOT23 -3 L TO -92 pro vide s a ver y sha rp turn -o n c ha ra cteristic, mak in g th ese d e vic es e xce lle nt rep la ce me nt fo r z en er d iod es in ma n y app lic ations. FEATURE P rogra mmab le o u tpu t v olta ge to 3 6V Lo w d yn a mic o utpu t impeda nce 0 .2Ω t yp ic al Sin k c urren t c ap ab ilit y of 1 .0 mA to 100 mA Equiva le n t fu ll-ra nge te mp era tu re co e fficien t of 50p p m/℃ typ ica l Temperature compensated for operation over full rated operating temperature range Lo w ou tpu t no ise vo lta ge Fa st turn o n re spo nse BLOCK DIAGRAM Page1 www.belling.com.cn V1.1 BL431 PIN CONNECTION ABSOLUTE MAXIMUM RATINGS Opera ting te mp era tu re ran ge app lies un le ss o therwise sp ec ified .) Charac te ristic S ymb o l Value Cath ode Vo ltag e Vka 37 Cath ode Cu rren t Ran ge Ika -10~+1 50 (co n tinuo us) Refe re nc e Inp ut Cu rren t R ang e IREF 10 TO -92 770 P ower Dissipa tion PD SOT23 -3 230 Opera ting Te mpe ra tu re Range Topr 0~+70 Store te mp e ra tu re Rang e Tstg -65~+1 50 Page2 www.belling.com.cn Unit V mA mA mW ℃ ℃ V1.1 BL431 ELECTRICAL CHARACTERISTICS (Ta=25℃ un less o the rwise sp ec ified ) P ara me te r Refe re nc e Vo lta ge Devia tion of Re fe re nce Inp ut Vo ltag e O ver Te mp era ture Ratio of the Change in Reference Voltage to the Change in Cathode Voltage Refe re nc e Inp ut Cu rren t Devia tion of Re fe re nce Inp ut Cu rren t O ver Te mp era ture Min imu m C athod e Curren t for Reg ula tion Off-Sta te Cu rren t D yn a mic Ou tpu t Imp ed anc e Cond ition s Vz=V R E F 0.5% Ii= 10 mA 1.0% S ymb o l Min 2.48 7 2.47 5 Typ 2.50 0 2.50 0 Max 2.51 3 2.52 5 Unit Vz=V R E F , Ii= 10 mA Vde v - 8.0 17 mV Δ VREF/ Δ Vz - -1. 0 -2. 7 - -0. 5 -2. 0 R1=10k Ω ,R2= ∞ I1=10 mA IREF - 2.0 4.0 μA R1=10k Ω ,R2= ∞ I1=10 mA ∝ IREF - 0.4 1.2 μA Vz=V R E F Iz (min) - 0.4 1.0 mA Vz=36V,V R E F = 0V Vz=V R E F , Iz=1 to 100 mA ,f< 1.0 kHz Iz (o ff) - 0.05 1.0 μA Rz - - 0.50 Ω Vz=V R E F ~10V Iz=1 0 mA Vz=10~36V VREF V mV/V TEST CIRCUIT II IN II IN R1 IREF I REF Iz Iz V REF IN R2 Vz Iz OFF VREF No te : V z=V R E F (1 +R1/R2 )+ I R E F *R1 1.Te st c ircu it for Vz=V R E F 2.Test c ircu it fo r V z>V R E F Page3 www.belling.com.cn 3 .Test c ircu it fo r o ff-sta te cu rre nt V1.1 BL431 APPLICATION CIRCUIT V+ V+ Vo VREF 30 R1 0.01uF R1 R2 Vo Vo = ( 1+R1/R2 ) V R2 REF Vo = ( 1+R1/R2 ) VREF 1 . Shun t Reg ula to r 2 . Series Regu la to r V+ IN LM7805 OUT 7805 Vo V+ COMMON R1 OUT IN R2 Vth=2.5V Von=2V Voff=V+ GND Vo = ( 1+R1/R2 ) V REF Vo M IN = V REF + 5 V 3.Ou tpu t C on tro l o f a Thre e 4 .S ing le Supp ly Co mpa ra to r with Termina l Fixed Reg u la tor Te mp erature Co mpe nsated Th re shold 5.Highe r C urre n t Sh un t Regu lator V+ Vo R1 R2 Vo=(1+R1 /R2) *V R E F Page4 6.Crow Ba r Vo V+ R1 R2 V limit= (1+R 1/R 2)*V R E F www.belling.com.cn V1.1 BL431 CHARACTERISTIC CURVES Page5 www.belling.com.cn V1.1 BL431 STABILITY BOUNDARY CONDITIONS: Test C ircu it fo r Sta b ility Bou nda ry: Page6 www.belling.com.cn V1.1 BL431 Appendix ： TO-92 Pac kag e Outlin e Dimen sion ： TO-92 ： Page7 www.belling.com.cn V1.1 BL431 SOT-23 -3 P ac ka ge Ou tline D imen sion ： Taping Diagram： ： Page8 www.belling.com.cn V1.1