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Microchip Technology TC1121CPA
- Part No.:
- TC1121CPA
- Manufacturer:
- Microchip Technology
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
TC1121CPA.pdf
- Description:
- IC REG CHARGE PUMP 100MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,003
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Product details
Overview
TC1121CPA from Microchip Technology is an 8-pin PDIP-packaged charge pump voltage inverter IC that converts 2.4V–5.5V input to a corresponding negative output voltage with up to 100 mA output current, 12 Ω typical output resistance, and selectable 10 kHz / 200 kHz oscillator frequency - used in medical instrumentation and μP-based controllers requiring compact, inductorless negative rail generation.
For engineers reviewing the TC1121CPA datasheet, TC1121CPA pinout, TC1121CPA application, or TC1121CPA equivalent, key selection criteria include shutdown quiescent current (≤1 µA), FC-controlled frequency scaling for capacitor size reduction, GND-referenced OSC pin for external clock synchronization, and compatibility with 10 µF–390 µF ceramic or tantalum charge-pump capacitors.
Technical Context
The TC1121CPA implements a two-phase switched-capacitor inverter topology with internal logic-driven switch matrix and RC oscillator. Its FC pin selects between 10 kHz (FC open) and 200 kHz (FC = V+) operation, directly impacting ripple frequency (5 kHz or 100 kHz) and minimum capacitor sizing.
It features a dedicated SHDN input enabling <1 µA supply current in shutdown mode, and an OSC pin supporting either external capacitor timing (sub-10 kHz) or CMOS-level external clock overdrive - both modes disable FC control while preserving full 100 mA output capability under load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 100 mA max - supports moderate-power analog rails or digital logic biasing without inductors. |
| Oscillator Frequency | 10 kHz (FC open) or 200 kHz (FC = V+) - enables trade-off between low quiescent current and small external capacitor footprint. |
| Supply Current | 50 µA typical at 10 kHz, <1 µA in shutdown - critical for battery-powered portable instruments. |
| Output Resistance | 12 Ω typical - determines voltage droop: e.g., −5.0 V → −3.8 V at 100 mA load from +5 V input. |
| Input Voltage Range | 2.4 V to 5.5 V - compatible with single-cell Li-ion, 3.3 V, and 5 V system rails. |
| Shutdown Logic | Active-low SHDN with VIH ≥ 0.8×V+, VIL ≤ 0.4 V - ensures robust interfacing with microcontroller GPIOs. |
| Package | 8-pin PDIP - through-hole mounting for prototyping, legacy industrial PCBs, and high-reliability solder joints. |
Pinout & Package
TC1121CPA uses an 8-pin plastic dual in-line package (PDIP) with 0.300-inch body width and 0.100-inch lead pitch, rated for 0°C to +70°C operation. Pin 1 is marked by a notch or dot; leads are tin-lead plated per standard Microchip PDIP specifications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (FC) | Frequency control input | Open = 10 kHz oscillator; tied to V+ = 200 kHz; no effect when OSC is externally driven. |
| 2 (CAP+) | Charge-pump capacitor positive terminal | Connects to C1 anode; carries bidirectional switching current >100 mA during pumping cycle. |
| 3 (GND) | Power-supply ground reference | Common return for V+, SHDN, FC, OSC; must be low-impedance for stable ripple performance. |
| 4 (CAP−) | Charge-pump capacitor negative terminal | Connects to C1 cathode; forms flying capacitor node with CAP+; referenced to GND during phase transitions. |
| 5 (VOUT) | Negative output voltage terminal | Delivers regulated-inverted voltage (e.g., −5 V from +5 V); sourced via C2 reservoir capacitor. |
| 6 (SHDN) | Active-low shutdown control | Pulling low reduces supply current to <1 µA; tie to V+ if unused to ensure active operation. |
| 7 (OSC) | Oscillator control/external clock input | Open = internal RC oscillator; add capacitor to GND for sub-10 kHz; accept CMOS clock for precise timing sync. |
| 8 (V+) | Positive input supply | Accepts 2.4–5.5 V; powers internal logic, switches, and oscillator; also serves as VIH reference for SHDN/FC. |
Key Features
| Feature | Design Value |
|---|---|
| Inductorless architecture | Eliminates EMI-sensitive magnetics and reduces BOM cost - ideal for space-constrained medical sensors. |
| Selectably scalable oscillator | 10× frequency range (10–200 kHz) allows optimization of capacitor size vs. quiescent current for each design. |
| Low-noise negative rail generation | Typical 90 mVpp ripple at 100 mA with 150 µF/0.2 Ω C2 - meets noise budgets for precision ADC references. |
| Robust shutdown interface | CMOS-compatible SHDN with guaranteed VIH/VIL thresholds ensures reliable wake/sleep control from MCU I/O. |
| Multi-topology flexibility | Supports cascading (for deeper negative voltages) and paralleling (for lower output resistance) without external logic. |
Applications
| Medical Instrumentation | Laptop Computers |
|---|---|
Use Scenario: Powering op-amp bias rails in portable ECG front-ends requiring clean ±5 V supplies from a single 3.3 V lithium battery. IC Role / Device Role / Timing Role: Negative voltage converter generating −3.3 V rail using 10 µF ceramic flying/reservoir caps and 200 kHz FC mode. Use Value: Eliminates need for discrete inductor-based inverters, reducing board area by >40% and EMI emissions in sensitive analog signal paths. |
Use Scenario: Providing −5 V for USB transceiver level-shifting and EEPROM programming voltage in legacy laptop docking stations. IC Role / Device Role / Timing Role: Inverter operating at 10 kHz (FC open) to minimize quiescent current during suspend mode. Use Value: Achieves <50 µA active supply current and <1 µA shutdown current - extends battery-backed suspend duration beyond 72 hours. |
| μP-Based Controllers | Disk Drives |
Use Scenario: Generating −12 V for RS-232 line drivers in industrial PLC I/O modules powered from 5 V backplane. IC Role / Device Role / Timing Role: Cascaded TC1121CPA pair (VOUT→V+ of second device) delivering −10 V at 60 mA. Use Value: Doubles output magnitude without external diodes or regulators - maintains 12 Ω ×2 effective output resistance for stable driver biasing. |
Use Scenario: Supplying −5 V to voice coil motor (VCM) preamp circuits in 2.5-inch HDD servo systems. IC Role / Device Role / Timing Role: Paralleled TC1121CPA pair reducing effective ROUT from 12 Ω to ~6 Ω for improved transient response. Use Value: Enables <500 ns step response to VCM current demand spikes - critical for track-following accuracy during seek operations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar charge pump inverter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX680CPA+ | Fixed 10 kHz oscillator; no FC pin; 100 mA output; requires 10 µF caps; SO8 only. | Lacks frequency scaling - less flexible for low-ripple or ultra-low-IQ designs. | Choose when fixed-frequency simplicity and MAXIM's long-term availability outweigh programmability needs. |
| ICL7660SIPAZ | 100 mA output; 10 kHz fixed; wider input range (1.5–12 V); 8-pin PDIP; higher 120 µA IQ. | Supports lower input voltages but consumes >2× more active current than TC1121CPA. | Prefer for 1.5–2.4 V input systems where TC1121CPA's 2.4 V min is insufficient. |
Compared with MAX680CPA+ and ICL7660SIPAZ, the TC1121CPA uniquely balances ultra-low 50 µA active current, 200 kHz frequency scalability for miniaturized capacitors, and PDIP packaging - making it optimal for cost-sensitive, space-constrained, or legacy-through-hole designs requiring dynamic power optimization.
Availability
TC1121CPA is available at Aetrix Electronics and suitable for medical instrumentation, laptop computing peripherals, and μP-based industrial controllers requiring stable component supply across extended product lifecycles.
Supply support for TC1121CPA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and power management ICs, with ISO/TS-16949 certified manufacturing and global technical support infrastructure.
The TC1121CPA belongs to Microchip's legacy charge pump converter family, designed specifically for inductorless negative voltage generation in portable, medical, and industrial systems where reliability and layout simplicity are prioritized over switching efficiency.
FAQ
What is the maximum continuous output current specification for the TC1121CPA?
The TC1121CPA delivers up to 100 mA of continuous output current into a resistive load while maintaining output regulation within datasheet limits. At 100 mA load, typical output voltage drops to −3.8 V from a +5 V input due to its 12 Ω output resistance. Derating is required above 70°C ambient, and short-circuit duration must not exceed 10 seconds per Absolute Maximum Ratings.
Can the TC1121CPA operate with an external clock source, and how does that affect the FC pin?
Yes, the TC1121CPA accepts an external CMOS-level clock applied to the OSC pin (Pin 7), overriding the internal oscillator. When OSC is externally driven, the FC pin (Pin 1) has no effect on frequency - the device synchronizes fully to the external signal. This enables precise timing alignment in multi-rail systems and eliminates oscillator drift in temperature-sensitive applications.
What is the recommended capacitor type and value for stable TC1121CPA operation at 200 kHz?
For 200 kHz operation (FC = V+), Microchip recommends 10 µF X7R ceramic capacitors for both C1 (CAP+/CAP−) and C2 (VOUT/GND), with ESR ≤ 0.2 Ω. Ceramic types minimize size and ESR-related losses; tantalum may be used for C2 if higher capacitance (>22 µF) is needed for ripple reduction, but C1 must remain low-ESR ceramic to handle peak switching currents in the TC1121CPA.
Does the TC1121CPA require special PCB layout considerations for low-noise performance?
Yes - TC1121CPA layout must minimize loop area for CAP+/CAP− and VOUT/GND paths, use solid GND plane beneath the IC, and place C1/C2 within 5 mm of their respective pins. OSC pin routing should avoid noisy traces; FC and SHDN lines require local decoupling. Poor layout increases ripple and can induce instability, especially at 200 kHz where parasitic inductance dominates.
Is the TC1121CPA still in active production, and what is its obsolescence status?
The TC1121CPA is marked "Obsolete Device" in Microchip's official documentation (DS20001358D), indicating it is no longer in active production. However, Aetrix Electronics maintains verified legacy inventory with full traceability and offers lifecycle management support, including cross-reference guidance and last-time-buy planning for ongoing production programs dependent on this 8-pin PDIP variant.
TC1121CPA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Ratiometric
- Output Configuration:
- Negative
- Topology:
- Charge Pump
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.4V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- -Vin
- Voltage - Output (Max):
- -
- Current - Output:
- 100mA
- Frequency - Switching:
- 10kHz ~ 200kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
TC1121CPA FAQ
1.How can I place an order for TC1121CPA through Aetrix?
Please submit a Request for Quotation (RFQ) for TC1121CPA on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TC1121CPA reliable?
The price and inventory of TC1121CPA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TC1121CPA is usually 5 days.
3.What payment methods are accepted for TC1121CPA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TC1121CPA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TC1121CPA?
TC1121CPA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TC1121CPA order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TC1121CPA?
For technical support, including TC1121CPA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TC1121CPA requirements.
6.How does Aetrix verify that TC1121CPA is sourced from the original manufacturer or authorized distributors?
All TC1121CPA products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TC1121CPA meets industry standards.
7.What is the process for return or replacement of TC1121CPA?
All TC1121CPA units undergo pre-shipment inspection (PSI). If there is an issue with TC1121CPA, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TC1121CPA part is unused and in its original packaging.
Return procedure for TC1121CPA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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