U2352B PWM Power Control for DC Loads Description The U2352B bipolar circuit is a PWM device for controlling logic level Power MOSFETs and IGBTs. It allows simple power control for dc loads. Integrated load current monitoring with adjustable switch-off threshold also gives the option of measuring the load current via the MOS transistor’s on-state resistance, RDS(on), or via a shunt resistor. Special Features Applications D Pulse width control up to 50 kHz clock frequency D D D D D D D Load current monitoring via the on-state resistance, RDS(on), of the FET or via shunt resistor (optional) D 100 mA push-pull output stage D Voltage monitoring D Temperature-compensated supply voltage limitation Battery-operated screwdrivers Battery-operated machine tools Halogen lamp controllers Dimmers Electronic fuses High-performance clock generators D Chip temperature monitoring Package: DIP8, SO8 VS 2xI S1 Oscillator 1 Chip temperature monitoring 140°C Reference voltage Voltage limitation 6.8 V 8 VS I – Output stage logic K1 + 2 Time window current measurement 3 Q S 7 Q R Push-pull output stage 6 GND – K2 + Load current monitoring POR 5 4 S2 95 9670 Figure 1. Block diagram TELEFUNKEN Semiconductors Rev. A1, 29-May-96 1 (8) C1 2 (8) R4 R3 R2 R9 I Set R7 R6 C3 R8 C2 C Osc V Control R5 4 3 2 1 I S1 2xI – K1 + Load current monitoring – K2 + S2 Q S POR Q R Chip temperature monitoring 140 °C Output stage logic Oscillator Time window current measurement VS 95 9671 5 GND 6 7 VS 8 *) R D RG D3 D2 D1 M T1 Load VB * Load current can also optionally be measured via shunt resistor Push-pull output stage Voltage limitation 6.8 V Reference voltage R1 U2352B Figure 2. Block diagram with typical circuit TELEFUNKEN Semiconductors Rev. A1, 29-May-96 U2352B Pin Description Osc 1 8 VS VContr 2 7 Output ISet 3 6 GND S2OUT 4 5 S2IN 95 9701 Pin 1 2 3 Symbol Osc VContr ISet 4 5 6 7 8 S2OUT S2IN GND Output VS Function Oscillator Control voltage input Setpoint value current monitoring Output, current switch S2 Input, current switch S2 Ground Output Supply voltage Supply, Pin 8 Pulse Width Control, Pins 1 and 2 Internal voltage limitation in the U2352B allows a simple supply via a series resistor R1. This enables operation of the circuit under different operating voltages. Supply voltage between Pin 8 (VS) and Pin 6 (GND) builds up via R1 and is smoothed by C1. At the frequency-determining capacitor, Cosc, at Pin 1, switching over of two internal current sources gives rise to a triangular voltage which comparator, K1, compares with the control voltage at Pin 2. If the voltage, V1, is more negative than the control voltage V2, the output stage is switched on via the output stage logic. When Cosc is charged, the whole process then runs in reverse order (see figure 3). The series resistor R1 is calculated as follows: R 1max + V *I V Bmin Smax tot where VBmin = Minimum operating voltage VSmax = Maximum supply voltage Itot = ISmax + IX ISmax = Maximum current consumption of the IS IX = Current consumption of the external elements Various thresholds are derived from an internal reference voltage source. Voltage Monitoring During build-up and reduction of the operating voltage, uncontrolled output pulses with excessively low amplitude are suppressed by the internal monitoring circuit. All latches are reset and the output of the load current detection Pin 4 is switched to ground. Chip Temperature Monitoring U2352B has integrated chip temperature monitoring which switches off the output stage when a temperature of approximately 140°C is reached. The device is not enabled again until cooling has taken place and the supply voltage has been switched off and then back on again. Load Current Monitoring, Pins 3, 4, 5 Load current can be measured with the aid of an external shunt resistor, but this is only appropriate for decreased loads due to additional power loss and component size and costs. This involves the shunt voltage being fed directly to Pin 4 via a protective resistor (see figure 5). In order to save component costs and additional power loss, the integrated load current monitoring allows the load current to be directly measured via the voltage drop at the on-state resistance, RDS(on), of the FET, without an additional shunt resistor. The drain voltage of the FET is supplied via an external protective resistor to Pin 5. During the off-state of the FET, a diode clamp circuit protects the detection input, Pin 5. In the on state, the load current flowing through the FET generates a corresponding voltage drop at its RDS(on), which is in turn converted into a current at Pin 5 by the protective resistor. This current reaches the integration element at Pin 4 via the switch S2, which is only closed in the on-state of the FET. If the voltage at Pin 4 exceeds the setpoint value set at Pin 3, as a result of a high load current, the shutdown latch is set and the output stage is blocked. To enable the circuit again, it is necessary to switch the operating voltage off and then back on again. Switch-off behavior is adjusted with the resistors at Pin 4 and Pin 5 and also with the capacitor at Pin 4. TELEFUNKEN Semiconductors Rev. A1, 29-May-96 3 (8) U2352B A time space, Dt, must be observed between switching the output stage off and on and switching S2 (current measurement enable switch) in order to avoid incorrect measurement and incorrect switching-off. To create this time window, the control voltage V2 is reduced internally about DV2 = approximately 300 mV and the resulting voltage, V2*, is compared with the triangular voltage, V1 (see figure 3). V 0.6 95 9672 VS V1 DV2 V2 V2* 0.3 VS V7 S2 closed open Dt Dt t Figure 3. Signal characteristics of pulse width control with time window generation Absolute Maximum Ratings Reference point Pin 6, unless otherwise specified Parameters Power supply current Pin 8 Pin 8 t < 10 ms Push-pull output stage Output current t < 2 ms Input currents Input voltages Storage temperature range Junction temperature Ambient temperature Pin 7 Pin 7 Pins 4 and 5 Pins 1 and 3 Pins 1, 2 and 3 Symbol Value Unit IS iS 40 400 mA ±IO ±iO ±II II VI Tstg Tj Tamb 20 100 10 2 0 to V8 –40 to +125 +125 –10 to +100 mA Symbol Maximum Unit RthJA 110 220 140 K/W mA V °C °C °C Thermal Resistance Parameters Junction ambient DIP8 SO8 on PC board SO8 on ceramic 4 (8) TELEFUNKEN Semiconductors Rev. A1, 29-May-96 U2352B Electrical Characteristics VS = 6 V, Tamb = 25_C, reference point Pin 6, unless otherwise specified Parameters Supply voltage limitation Current consumption Voltage monitoring Switch-on threshold Switch-off threshold Oscillator f OSC [kHz] Pin 8 Pin 8 [C Upper threshold (0.6 VS) Lower threshold (0.3 VS) Charge current Discharge current Control voltage input Input voltage range Input current, Offset voltage K1 Window, current measurement Load current monitoring Setpoint value input: Input voltage range Input current Offset voltage K2 Load current detection: Voltage limitation Voltage limitation Discharge current at POR Switch S2 Residual voltage at closed switch Push-pull output stage Upper saturation voltage Lower saturation voltage Output current ON state OFF state Test Conditions / Pins IS = 5 mA Pin 8 IS = 20 mA VS = 6 V Pin 8 OSC 0 V ≤ V3 ≤ 6 V I5 = 1 mA I5 = –1 mA TELEFUNKEN Semiconductors Rev. A1, 29-May-96 IS Typ. 6.8 6.9 2.7 Max. 7.2 7.3 3.5 Unit V mA 5.2 4.7 5.6 5.1 6.0 5.5 V VTu VTl –Ich Idis 3.4 1.7 26 26 3.6 1.8 33 33 3.8 1.9 40 40 V V mA mA Pin 2 Pin 2 Pin 2–1 Pin 2–1 VI ±Ii ±VOffs –DV2 0 300 V8 500 15 340 V nA mV mV Pin 3 Pin 3 Pin 4–3 VI ±Ii ±VOffs 6 500 15 V nA mV Pin 1 Pin 5 Pin 5 Pin 4 Pin 5–4 V4 = 0 V, I5 = 50 mA V4 = 0.1 V, I5 = 50 mA V4 = 0.3 V, I5 = 50 mA V4 = 0.3 V, I5 = 100 mA Pin 7 I7 = –2 mA Pin 7–8 I7 = 10 mA Pin 7 t ≤ 2 ms t ≤ 2 ms Min. 6.4 6.5 VSON VSOFF 55 [nF] V S [V] 0 V ≤ V2 ≤ V8 Symbol VS VL –VL Idis 260 0 2.3 0.7 1 VSat mA 175 150 125 200 –VSatu VSatl –io io V mV 1 0.3 100 100 V V mA 5 (8) U2352B 1000 R9=1MW VIN RD = 20 kW 500KW VOUT ( mV ) 800 5 100KW 50KW 600 20KW 400 10KW S2 4 200 5KW 95 9673 0 0 VOUT R9 200 400 600 800 1000 VIN ( mV ) 95 9686 Figure 4. Typical circuitry of the current switch S2 with associated transfer characteristics (S2 closed) VB R1 R2 82 kW D2 1 8 D3 680 pF 10 kW R6 47 kW R3 Speed 68 kW R7 27 kW Load D1, T1 and Rsh are load dependent Cosc C1 4.7 mF M D1 R5 33 kW T1 2 7 R8 RG C2 470 nF Torque U2352B 3 6 4 5 C4 R4 1kW R9 C3 10 nF 95 9674 1.5 kW Rsh GND Figure 5. Speed control with load current monitoring (load current detection via shunt resistor) 6 (8) TELEFUNKEN Semiconductors Rev. A1, 29-May-96 U2352B Dimensions in mm Package: DIP8 94 8873 Package: SO8 94 8862 TELEFUNKEN Semiconductors Rev. A1, 29-May-96 7 (8) U2352B Ozone Depleting Substances Policy Statement It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances ( ODSs). The Montreal Protocol ( 1987) and its London Amendments ( 1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2 . Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency ( EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances ) respectively. TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use TEMIC products for any unintended or unauthorized application, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 ( 0 ) 7131 67 2831, Fax number: 49 ( 0 ) 7131 67 2423 8 (8) TELEFUNKEN Semiconductors Rev. A1, 29-May-96