-SQA-SCOTTISH QUALIFICATIONS AUTHORITY HIGHER NATIONAL UNIT SPECIFICATION GENERAL INFORMATION

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1 -SQA-SCOTTISH QUALIFICATIONS AUTHORITY HIGHER NATIONAL UNIT SPECIFICATION GENERAL INFORMATION -Unit Number Superclass- -Title- XL ANALOGUE ELECTRONIC DEVICES DESCRIPTION- GENERAL COMPETENCE FOR UNIT: Analysing the use of diodes and transistors in analogue applications. OUTCOMES 1. analyse the operating characteristics and applications of semi-conductor diodes; 2. analyse the properties and operation of npn and pnp bipolar transistors; 3. analyse the properties and operation of Field Effect Transistors (FET). CREDIT VALUE: 1 HN Credit ACCESS STATEMENT: Access to this unit is at the discretion of the centre. However, it would be beneficial if the candidate had a basic understanding of d.c. and a.c. circuit principles. This may be evidenced by possession of Higher Grade Physics and/or NC module: Electrical Fundamentals; Circuit Elements; Single Phase A.C.; D.C. and A.C. Circuit Responses or similar qualifications or experience For further information contact: Committee and Administration Unit, SQA, Hanover House, 24 Douglas Street, Glasgow G2 7NQ. Additional copies of this unit may be purchased from SQA (Sales and Despatch section). At the time of publication, the cost is 1.50 (minimum order 5.00).

2 HIGHER NATIONAL UNIT SPECIFICATION STATEMENT OF STANDARDS UNIT NUMBER: UNIT TITLE: ANALOGUE ELECTRONIC DEVICES Acceptable performance in this unit will be the satisfactory achievement of the standards set out in this part of the specification. All sections of the statement of standards are mandatory and cannot be altered without reference to SQA. OUTCOME 1. ANALYSE THE OPERATING CHARACTERISTICS AND APPLICATIONS OF SEMICONDUCTOR DIODES PERFORMANCE CRITERIA (a) (b) Current-Voltage (I-V) curves are correctly drawn and operating characteristics clearly identified for signal and zener diodes in accordance with a given specification. Circuits containing signal, zener and light emitting diodes are correctly analysed and currents and voltages compared with measurements obtained from a practical circuit. RANGE STATEMENT Operating characteristics: forward bias; reverse bias; reverse breakdown; threshold voltage; dynamic resistance. Applications: rectifying; clipping; clamping. EVIDENCE REQUIREMENTS Written and performance evidence is required to show that the candidate can analyse circuits containing semiconductor diodes covering the full range statements as defined for performance criteria (a) and (b). 2

3 OUTCOME 2. ANALYSE THE PROPERTIES AND OPERATION OF NPN AND PNP BIPOLAR TRANSISTORS PERFORMANCE CRITERIA (a) (b) (c) (d) Operating principles of the bipolar transistor are correctly described. Current-voltage characteristics for a bipolar transistor are correctly sketched and described. A common-emitter transistor bias circuit is correctly drawn and component values calculated for a given Q point. Manufacturer s data sheets for bipolar junction transistors are correctly interpreted. RANGE STATEMENT Properties: collector current; base-emitter, collector-base and collector-emitter voltages; saturation, cut-off and active regions; current gain; input and output resistance. EVIDENCE REQUIREMENTS Written evidence is required to show that the candidate can analyse the properties and operation of bipolar transistors covering the full range statement as defined for performance criteria (a) - (d). OUTCOME 3. ANALYSE THE PROPERTIES AND OPERATION OF FIELD EFFECT TRANSISTORS (FET) PERFORMANCE CRITERIA (a) (b) (c) Operating principles of FET transistors are correctly described. A common source transistor bias circuit is correctly drawn and the values of bias components correctly calculated to produce a given Q-point. A common source single stage n-channel transistor bias circuit is correctly constructed and tested. RANGE STATEMENT Field effect transistors: n-channel and p-channel JFET; enhancement and depletion MOSFET. 3

4 EVIDENCE REQUIREMENTS Written and performance evidence is required to show that the candidate can analyse the properties and operation of FET transistors covering the full range statements as defined for performance criteria (a) - (c). MERIT To gain a pass in this unit, a candidate must meet the standards set out in the outcomes, performance criteria, range statements and evidence requirements. To achieve a merit in this unit, a candidate must demonstrate a superior or more sophisticated level of performance. This may be demonstrated by: (i) (ii) his/her aptitude in the construction and testing of the practical circuits; the application of the theory to correctly solve unfamiliar problems ASSESSMENT In order to achieve this unit, candidates are required to present sufficient evidence that they have met all the performance criteria for each outcome within the range specified. Details of these requirements are given for each outcome. The assessment instruments used should follow the general guidance offered by the SQA assessment model and an integrative approach to assessment is encouraged. (See references at the end of support notes). Accurate records should be made of the assessment instruments used showing how evidence is generated for each outcome and giving marking schemes and/or checklists, etc. Records of candidates achievements should be kept. These records will be available for external verification. SPECIAL NEEDS Proposals to modify outcomes, range statements or agreed assessment arrangements should be discussed in the first place with the external verifier. Copyright SQA 1997 Please note that this publication may be reproduced in whole or in part for educational purposes provided that: (i) (ii) no profit is derived from the reproduction; if reproduced in part, the source is acknowledged. 4

5 HIGHER NATIONAL UNIT SPECIFICATION SUPPORT NOTES UNIT NUMBER: UNIT TITLE: ANALOGUE ELECTRONIC DEVICES SUPPORT NOTES: This part of the unit specification is offered as guidance. None of the sections of the support notes are mandatory. NOTIONAL DESIGN LENGTH: SQA allocates a notional design length to a unit on the basis of time estimated for achievement of the stated standards by a candidate whose starting point is as described in the access statement. The notional design length for this unit is 40 hours. The use of notional design length for programme design and timetabling is advisory only. PURPOSE The purpose of this unit is to provide a foundation in the theories and analysis techniques required in the application of standard analogue devices. The unit is intended to provide candidate with both theoretical and practical expertise and should be taught and assessed in that manner. CONTENT/CONTEXT Corresponding to outcomes: Outcome 1 Diodes: the p-n junction, holes and electrons, forward and reverse bias, reverse breakdown, threshold voltage, dynamic resistance. Circuit symbols. Models: forward bias; battery with resistor, and reverse bias model. Rectifying, clipping and clamping circuits. Calculation of circuit voltages and currents. Outcome 2 Bipolar transistors: principles of operation, current-voltage characteristics of common-emitter connected transistor, current gain and input and output resistance (conductance). Common emitter bias circuit analysis and design. Data sheets in terms of collector current, collector-base and collector-emitter voltages, current gain. Outcome 3 FET transistors: principles of operation, current-voltage characteristics of common-source connected JFET, current gain and input and output resistance. Common-source bias circuit analysis and design. Common-source amplifier input/output characteristics. Data sheets in terms of gate-source reverse current and breakdown voltage, saturation drain current, gate-source voltage, transductance. 5

6 APPROACHES TO GENERATING EVIDENCE The use of written tests to enable the candidate to demonstrate competence in the analysis of circuits coupled with appropriate build and test laboratory exercises are appropriate assessment methods. ASSESSMENT PROCEDURES Centres may use Instruments of Assessment which are considered by tutors/trainers to be most appropriate. Outcome 1 could be assessed by drawing a typical I-V curve and identifying the operating characteristics as defined in the range statement. A written test could be used to show that the candidate can use a correct method to analyse circuits containing one or more diodes. A laboratory exercise could be used in which the candidate obtains measurements from a practical circuit. Outcome 2 could be assessed by a written test of the candidate s ability to describe the properties and operating principles of a bipolar transistor and to use a correct method to calculate bias component values. An oral test could be used to determine the candidate s ability to correctly select three parameters from a given transistor data sheet. Outcome 3 could be assessed by a written test of the candidate s ability to describe FET transistors and to use a correct method to calculate bias component values. Evidence of actual performance is required of the candidate s ability to correctly construct and test a given single stage commonsource FET circuit and could be assessed by a practical exercise. The assessment of outcome 3 performance criteria (b) and (c) could be assessed by a single design, build and test exercise. PROGRESSION Achievement of this unit would provide a sound basis for access to unit Operational Amplifiers. REFERENCES 1. Guide to unit writing. 2. For a fuller discussion on assessment issues, please refer to SQA s Guide to Assessment. 3. Information for centres on SQA s operating procedures is contained in SQA s Guide to Procedures. 4. For details of other SQA publications, please consult SQA s publications list. A support pack for this is available from SQA. Please call our Sales and Despatch section on to check availability and costs. Quote product code C084. 6

7 Copyright SQA 1997 Please note that this publication may be reproduced in whole or in part for educational purposes provided that: (i) (ii) no profit is derived from the reproduction; if reproduced in part, the source is acknowledged. 7