NJM2823 Precision Micropower Shunt Voltage Reference ■GENERAL DESCRIPTION ■PACKAGE OUTLINE NJM2823 is a precision and low quiescent current shunt voltage reference. Reference voltage form bandgap circuit has guaranteed the high accuracy of the ±0.4% with trimming. In addition the temperature drift of 15ppm/°C typ. was actualized by the temperature compensating circuit. The reference voltage circuit operates by consumed low quiescent current of the 60µA for low power technology. The Output capacitor is unnecessary by the phase compensating circuit which is built in. Tolerates capacitive loads, it is easy to use for application. It is suitable for data converters, instrumentation, and other applications where precision reference is required. ■FEATURES ● Precision Reference Voltage 1136mV±0.4% ● Low temperature coefficient 15ppm/°C typ. ● Low Quiescent Current 60µA max. ● No Output Capacitor Required ● Tolerates Capacitive Loads ● Bipolar Technology ● Package Outline NJM2823F : SOT-23-5 (MTP5) NJM2823F ■PRODUCT VARIATION NJM2824** Small PKG NJM2823 ±0.4%, IMIN=60µA NJM2820 ±0.7%, IMIN=500µA ** Planning ■BLOCK DIAGRAM ■PIN CONFIGURATION CATHODE 5 CATHODE NC 1 ANODE 2 VREF NC 3 FB 4 FB NJM2823F ANODE Ver.2009-03-05 -1- NJM2823 ■ABSOLUTE MAXIMUM RATINGS (Ta=25°C) PARAMETER SYMBOL Cathode Voltage VKA Cathode Current IK Cathode-Anode Reverse Current -IK Power Dissipation PD Operating Temperature Range TOPR Storage Temperature Range TSTG MAXIMUM RATINGS 14 20 10 200 -40 ∼ +85 -40 ∼ +125 ■RECOMMENDED OPERATING CONDITIONS (Ta=25°C) PARAMETER SYMBOL MIN. TYP. Cathode Voltage Cathode Current VKA IK VREF 0.06 MAX. UNIT 13 12 V mA – – ■ELECTRICAL CHARACTERISTICS (IK=100µA,Ta=25°C) PARAMETER SYMBOL TEST CONDITION Reference Voltage Load Regulation Reference Voltage Change vs. Cathode Voltage Change Minimum Operating Current Feedback Current Dynamic Impedance MIN. TYP. MAX. UNIT VREF ∆VREF/ ∆IK VFB=VA VFB=VA, IMIN≤ IK≤ 1mA VFB=VA, 1mA≤ IK≤ 12mA (*1) (*1) (*1) 1131.5 – – 1136.0 0.15 1.5 1140.5 1.1 6 mV mV mV ∆VREF/ ∆VKA VREF≤ VKA≤ 13V, R1=120kΩ, R2=val (Note 1) (*2) – -0.52 -2.8 mV/V IMIN VFB=VA (*1) – 20 60 µA IFB R1=∞, R2=120kΩ VFB=VA, f≤ 120Hz, IK=1mA, IAC=0.1IK (*2) – 100 200 nA (*1) – 0.1 – Ω MIN. TYP. MAX. UNIT ZKA ■TEMPERATURE CHARACTERISTICS (IK=100µA, Ta=-40°C ∼ 85°C) PARAMETER SYMBOL TEST CONDITION Reference Voltage Change (Note 2) Reference Input Current Change UNIT V mA mA mW °C °C ∆VREF_T ∆IFB_T VFB=VA (*1) – 5.7 15 8.2 50 mV ppm/°C R1=∞, R2=120kΩ (*2) – 200 – nA Note 1: VREF···Reference voltage includes error. Note 2: Reference Voltage Change is defined as ∆VREF_T [mV] = ± <VREF × 0.4%> ± < Reference Voltage Change [ppm/°C] > × <-40°C ∼ 25°C> × ＶＲＥＦ . The maximum value of “Reference Voltage Change” is determined based on sampling evaluation from the 5 initial production lots, and thus not tested in the production test. Therefore, these values are for the reference design purpose only. (*1): Test Circuit (Fig.1) (*2): Test Circuit (Fig.2) -2- Ver.2009-03-05 NJM2823 ■TEST CIRCUIT Input VKA Input VKA IK VREF IK CATHODE VREF R1 FB CATHODE FB R2 ANODE IFB Fig.1 VKA=VREF to test circuit ANODE Fig.2 VKA>VREF to test circuit R2 VKA = VREF1 + + IFB × R2 R1 VFB=VA Reference Voltage vs. Cathode Current Reference Voltage vs. Temperature (IK=100µA, VFB=VA) 6 o Reference Voltage VREF (mV) Reference Voltage ∆VREF (mV) ■TYPICAL CHARACTERISTICS 4 2 0 -2 -4 -6 -50 (V =V , Ta=25 C) FB 1140 1139 1138 1137 1136 1135 1134 0.01 -25 0 25 50 75 100 125 o Ambient Temperature Ta ( C) Reference Voltage vs. Cathode Current (mV) REF Reference Voltage V Reference Voltage VREF (mV) A 1200 1100 1000 900 800 0 Ver.2009-03-05 20 40 60 80 Cathode Current IK (µA) 100 o (V =V , Ta=25 C) FB 0.1 1 10 Cathode Current IK (mA) Reference Voltage vs. Cathode Voltage o 1300 A 100 1150 (R1=120kΩ, R2=val, IK=100µA, Ta=25 C) 1145 1140 1135 1130 1125 1120 0 2 4 6 8 10 12 Cathode Voltage VKA (V) 14 -3- NJM2823 ■TYPICAL CHARACTERISTICS Dynamic Impedance (IK=1mA, V =V , Ta=25 C) FB 200 A Feedback Current vs. Temperature (R1=Open, R2=120kΩ, IK=100µA) (nA) 14 FB 12 Feedback Current I Dynamic Impedance |ZKA| (Ω) o 10 8 6 4 2 0 0.01 0.1 1 10 100 Cathode Current Frequency f (kHz) 150 100 50 0 -50 -25 0 25 50 75 100 125 o Ambient Temperature Ta ( C) Sefty Operating Boundary Condition (V =V , Ta=25oC) FB Cathode Current IKA (mA) 1.5 1.25 A Ceramic Capacitor 1 0.75 Stable Operation Region 0.5 Unstable Operation Region 0.25 0 0.001 0.01 0.1 1 Output Capacitance Co (µF) Note) Oscillation might occur while operating within the range of safety curve. So that, it is necessary to make ample margins by taking considerations of fluctuation of the device. 10 Power Dissipation vs. Temperature (MTP5=Itself, Tj= ∼125oC) Power Dissipation PD (mW) 250 200 150 100 50 0 0 -4- 25 50 75 100 o Ambient Temperature Ta ( C) Ver.2009-03-05 NJM2823 ■Application Information The NJM2823 creates a highly accurate reference voltage, enabling a low power consumption application circuit to be configured. In the basic application (Fig.1) of the shunt regulator, a voltage drop is created by resistor Rs connected between the input voltage and the NJM2823, and the output voltage (cathode – anode voltage = VKA) is controlled to a constant value. The voltage drop due to Rs is determined by the total of the output current and the cathode current. The feedback to the output voltage is controlled by the FB terminal, and the cathode current changes so that the set voltage is obtained. VIN As a result, Rs must conform to the following conditions. *Minimum cathode current = 60 uA min Conditions under which the input voltage is a minimum and the output current is a maximum. R1 RS VOUT=VKA IK VREF CO *Maximum cathode current = 12 mA max Conditions under which the input voltage is a maximum and the output current is a minimum. R2 IFB The value of resistor Rs is obtained by means of the following formula. RS = Fig.1 basic application VIN − VOUT [Ω] IK + IOUT The output voltage can be set using any desired value between VREF and 13 V. The output voltage is set according to the ratio between the values of the two external resistors, however an error occurs depending upon the feedback current. The error can be minimized by combining two external resistors with low resistance values. The formula for calculating the output voltage setting is shown below. R2 VOUT = + 1 × VREF + IFB × R2 R1 As shown in the “reference voltage versus cathode voltage” characteristics example, the reference voltage value has negative characteristics. The reference voltage is corrected by using ∆VREF/∆VKA stipulated by the electrical characteristics. ∆V ∆VREF = REF ∆VKA × VOUT VKA (V) 1.20 1.50 1.80 2.50 3.30 5.00 R1 (kΩ) Open 120 120 120 120 120 R2 (kΩ) Short 38.2 69.5 142.8 226.4 404.3 Table.1 Examples of output voltage settings at the standard Table 1 shows an example of combining constants in the case where R1 is assumed to be 120 kΩ. The error in the output voltage also varies with the accuracy of the resistors. In order to realize a highly accurate application, the relative accuracy can be improved by either using accurate resistors or combining integrated resistors. The NJM2823 contains an optimized phase compensation circuit. Consequently, in the basic application a stable reference voltage is generated without the use of an output capacitor. As is indicated in the “dynamic impedance versus frequency” characteristics, the impedance increases in proportion to the frequency. If necessary, connect an output capacitor to reduce the high frequency impedance. You can connect a ceramic capacitor to obtain high stability, but in this case be sure to use the NJM2823 in the stable operation region while referring to the “stable operation boundary conditions” characteristics example. Ver.2009-03-05 -5- NJM2823 MEMO [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. -6- Ver.2009-03-05