NJM UNIERSAL SINK DRIER GENERAL DESCRIPTION NJM is a bipolar universal high-current highly protected low side driver with transparent input and ma continuous -current sink capability. A high-level input activates the output. The driver is equipped with extensive electrical protection; such as over current protection and thermal protection, which makes the device virtually indestructible. Furthermore it can detect open circuit and short circuit to ground. A special feature is the Error indicating output function pin which signals to the host system if the protection or the load check functions is activated. The NJM and NJM8 are complementary drivers and have similar data. PACKAGE OUTLINE NJMTA FEATURES ma continuous-output current Short circuit to CC protection Error signal to host system Open circuit detection Short circuit to ground detection Thermal protection Built-in protection diodes Package TO- (-pin) BLOCK DIAGRAM Supply NJM To logic oltage reference Thermal protection Error Q S R Short-circuit to cc protection Short-circuit to detection Open circuit detection Figure. Block Diagram
NJM PIN CONFIGURATION NJMTA Error Supply Figure. Pin description PIN DESCRIPTION TO- Symbol Description Supply Supply voltage. Nominally to. pin. Current flows from supply through the load into the pin. Nominal current is 8 ma to A. Ground supply. diode are bonded to a separate pin. Error Error indicating pin. Sinks current to ground if the protection and/or detection circuitry is activated. Note: the current must be externally limited to 8 ma. TTL compatible input. A LOW input signal turns the output transistor off and a HIGH input turns it on. voltage cc. NJM Active output Overload or short circuit to cc Error voltage % cc NJM Inactive output Normal operation..6. Open circuit I OMIN (min. ma, max 8 ma) Normal operation Short circuit to error Short circuit protection IOS (min A, max. A) current 7% % % cc cc cc Short circuit to Error Figure. Error state vs. output voltage and output current, active output (. IN CC ), < CC <, - C <T J < + C Figure. Error state vs. output voltage, inactive output ( IN.8 ), CC, - C < T J < + C
NJM FUNCTIONAL DESCRIPTION The circuit NJM is a low side driver capable of driving resistive or inductive loads not exceeding A. The driver has an error indicating function which generates an Error output signal when a fault condition has occurred. The circuits NJM and NJM8 are complementary drivers with equivalent functions and similar data. NJM is a sink driver and NJM8 is a source driver. stage The output stage is switched on and off according to the status of the input. HIGH level activates the output. If the input is left open, the circuit will accept it as a LOW level. stage The output stage contains a power transistor and two clamping diodes. The diodes are used for terminating line transients from inductive loads. If the driver is inactive and the output is shorted to the driver will leak maximum 8 µa. See figure 8. Protection circuit The circuit contains two protection circuits: Overload and Short circuit protection Thermal protection The overload and short circuit protection will be activated at I out =. A typically at T J = + C, see figure. The output will be turned off immediately and latched to a high-impedance state after an overload or short circuit has been detected. I Ref CC Figure. stage Figure 6. stage Fault condition Error How to resume normal operation LOW=Error HIGH=Normal Normal LOW OFF HIGH HIGH ON HIGH OUT Short to LOW OFF LOW Remove fault condition. HIGH ON LOW Remove fault condition. OUT Short to CC LOW OFF HIGH HIGH OFF LOW Turn off and on after fault condition is removed. Open load LOW OFF HIGH HIGH ON LOW Attach proper load to output or turn off the driver. Over temperature LOW OFF HIGH T J = C HIGH OFF LOW Temperature is reduced to approx C, or turn off the driver. Figure 7. Error table
NJM A logic-level change at the input will reset the internal error latch. If the fault still is present at turn-on, the circuit will once again turn the output off. Due to a slight delay in the circuit, a high current transient will occur when the output is shorted to cc. This current transient may reach 8 A during µs. Consequently, switching at high frequencies with a shorted output may destroy the circuit. If a short circuit condition is detected, stop switching the input and remove fault condition. Thermal protection The output of NJM is equipped with a thermal shut-down function, that turns the outputs off at a chip (junction) tenperature above typically C. Normal operation is resumed when the temperature has decreased about C. Error functions The Error indicating signal occurs on a separate pin. The complete error table is shown in figure 7. The following conditions generate an error signal: When the driver is activated and at least one of the following conditions has occurred: thermal overload short circuit to short circuit to CC open circuit An output current less than 8 ma might be detected as open circuit. currents larger than 8 ma and less than A will definitely not generate an error. The normal operational area is shown in figure. Also when the driver is inactivated an Error indication can occur. That is if the output is shorted to. In figure short circuit to Error state versus output voltage is shown. When the Error-detection function is activated, the Error output is capable of sinking 8 ma, supporting direct connection of an LED. The current has to be externally limited by a series resistor. Signal diagrams The signal diagram in figure 8 shows the input signal and the resulting output signals for each error mode. For details, see error table, figure 7. IN = voltage. Active = HIGH. OUT = voltage. I OUT = current from driver. ERR = Error output voltage. Error = LOW. IN I OUT OUT * Err > < Normal operation Overload or short circuit Short circuit to Open circuit * Undefined level Over temperature Figure 8. Signal diagram
NJM ABSOLUTE MAXIMUM RATINGS Parameter Pin no. Symbol Min Max Unit oltage Supply voltage CC Logic input voltage IN -. CC Current Logic input current I IN - - ma Continuous DC Operation output current TO- I OUT - ma Error output current I ERR - ma Temperature Operating junction temperature (internally limited) T J - + C Storage temperature T S - + C Power Dissipation (Package Data) Power dissipation at T Case = 8 C, TO- package P D - W ESD ESD tolerance (Note ) - RECOMMENDED OPERATING CONDITIONS Parameter Symbol Min Typ Max Unit Supply voltage CC.7 - current TO- I OUT - - ma Operating junction temperature T j - - + C Error output current I Err - 8 ma I IN I IH I IL IN IH IL IErr Error NJM Fault Detector Supply I CC I OUT I OS I OMIN I OL Supply voltage + C Load High level Low CC voltage High ON tphl OFF % 9 % % % t of SAT Err CE SAT CC level Low % CC 9 % voltage % tplh % tor Figure 9. Definition of symbols Figure. Timing diagram, input vs. output. CC =
NJM ELECTRICAL CHARACTERISTICS At CC, - C T J + C. Typical values are given at CC =, T J = C Parameter Symbol Conditions Min Typ Max Uni General Supply current I CC IN.8. 7 ma Thermal shutdown T JS - + - C Logic input High level input voltage IH. - CC Low level input voltage IL -. -.8 High level input current I IH. IN CC - 9 µa Low level input current I IH IN.8 - - - µa s Error output saturation voltage Err SAT I Err = ma -. saturation voltage CE SAT I OUT = A -..8 current shutdown I OS. IN CC... A current I OMIN. IN CC. 8 ma (not detected as open circuit) leakage current I OL IN.8. = -8-6 - µa Clamping diode forward voltage I F =. A -..8 Timing Propagation time I OUT = A high to low (%), t phl -.. µs low to high (%), t plh -.. µs Rise time ( to 9%), t or -.. µs Fall time (9 to %), t of -.. µs THERMAL CHARACTERISTICS Parameter Symbol Conditions Min Typ Max Unit Thermal resistance Rth j-c TO- package, junction to case - - C/W Rth J-A TO- package, junction to ambient - 6 - C/W Notes:. Currents are defined positive if flowing into, and negative if flowing out of a terminal. oltages are defined between terminal and ground.. ESD testing according to Human Body Model (C Zap = pf, R Zap = Ω)
NJM APPLICATIONS INFORMATION Important application areas are: Programmable logic control systems Relay control Hydraulic valves Intelligent interfaces between microprocessors and loads Robot techniques Print head drivers High-current stepper motor drivers Transient protection. Keep CC and leads as short as possible.. Connect a filter capacitor close to the circuit. Recommended filter capacitor between CC and is 6.8 µf, of tantalum type. A ceramic capacitor in parallel will improve high frequency decoupling. Typical values range from. µf to. µf. In an application having a highly stable supply and short power leads to the driver a low leakage electrolytic type can be used, which is less expensive.. Connect and Error via pull-up resistors to the appropriate logic supply level or CC to obtain highest noise immunity. See figure. The resistor R limits the current into the Error indicating pin. This current must not exceed 8 ma. R is a pull-up resistor which improves noise immunity at the. Pull-up current should not exceed the sinking capacity of the controlling device output.. If several supply voltages are to be used, prefere a supply having separate ground leads. In this case the logic ground and the power ground should be connected together at only one point, the ground pin of the driver. Switch mode applications The internal diodes are normally sufficient for clamping of transients caused by inductive load turn off. External diodes may be necessary in PWM/switch mode applications, and when the terminals are externally accessible and thereby exposed to an electrically noisy environment. Recommended diodes are BY7/, BY98/, UF or similar types with a t rr < ns and I F A. Error indication signal When the circuit is switched on/off, a short pulse (t Err < µs for resistive loads) is generated at the Error output. This is a correct detection of an incorrect level during the rise and fall times of the output voltage. Consequently the Error output should not be detected when switching on and off. An alternative is to low-pass filter at the Error output at around khz. Heat sinking NJMN is packaged in a -pin TO power package. The circuit is connected to the heat sink tab. External heatsinking is achieved by mounting the package to a heat sink.
NJM Supply voltage + max. + TTL, LS-TTL, CMOS µp, controller R R kω NJM Error To logic cc oltage reference Q S R Thermal protection Short-circuit to cc protection Short-circuit to detection Open circuit detection Load + 6.8µF Figure. Typical application. Pin numbers refer to TO package Maximum allowable power dissipation [W] TO Package 6 b * c a - - 6 8 Temperature [ C] a. Ambient temperature. No heatsink. Rth J-A =6 C/W. b. Mounted on heatsink. Rth J-A = C/W @ W. c. Case temperature. Rth = C/W. Figure. Maximum allowable power dissipation. TO package J-C
9 NJM TYPICAL CHARACTERISTICS I cc (ma) 8 - C < T J < C I F (A)..6 T J = C I IN (µ A) - C < T J < C 6 6..8 8. cc () Figure. Current consumption vs. supply voltage at in.8 (Inactive output)..8..6. F () Figure. Diode forward voltage drop vs. forward current..... IN () Figure. current vs. input voltage CC I ERR (ma) I OUT (A) I OL (µa) - 6 T J = C T J = C -6 - - C < T J < C 8-8 - 6 8 ERR () Figure 6. Error output saturation voltage vs. error current. CC = P DIS (W) 6..8..6.. CE SAT () Figure 7. saturation voltage vs. output current. < CC < I OS (A) CC () Figure 8. leakage current vs supply voltage. IN.8 =...... I OUT (A) 9 - - 6 T J ( C) 9 8 Figure 9. Power dissipation vs. output current Figure. Typical output current shut-down vs. chip temperature. CC 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.