Texas Instruments TL7660ID

Overview

TL7660ID from Texas Instruments is a CMOS switched-capacitor voltage converter that generates a regulated negative output voltage (–V_CC) from a positive input supply (1.5 V to 10 V), operating across –40°C to +125°C. It requires only two external noncritical capacitors, delivers up to 20 mA output current, achieves 99.9% open-circuit voltage conversion efficiency, and integrates an internal RC oscillator with nominal 10 kHz frequency at 5 V - used in portable instrumentation power rails and low-noise analog front-ends.

For engineers reviewing the TL7660ID datasheet, TL7660ID pinout, TL7660ID application, or TL7660ID equivalent, key selection criteria include its wide 1.5–10 V input range, latchup-proof substrate biasing logic, LV terminal configuration for low-voltage operation (<3.5 V), SOIC-8 package compatibility, and absence of external diodes across temperature and voltage ranges.

Technical Context

The TL7660ID implements a four-MOSFET charge-pump topology with p-channel S1 and n-channel S2–S4 switches, controlled by an internal RC oscillator and voltage-level translator. Its anti-latchup logic continuously monitors V_OUT and dynamically biases switch substrates to maintain reverse-biased source-substrate junctions under all load and startup conditions.

Operation supports dual modes: negative voltage conversion (V_OUT = –V_CC) and voltage doubling (V_OUT ≈ 2V_CC – 2V_F), with oscillator frequency adjustable via external capacitor on OSC pin or overdrive with external clock (1-kΩ series resistor required).

Key Specifications

Pinout & Package

TL7660ID is housed in an 8-pin SOIC (D) package with 1.27 mm pitch, JEDEC MS-012AC compliant, and rated for surface-mount reflow per Level-1-260°C MSL.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage converter applications.

Compared with ICL7660SIPAZ and MAX1044CPA+, the TL7660ID offers superior high-temperature reliability (125°C), eliminates external diodes across its full range, and provides dedicated LV control for sub-3.5 V operation - making it the optimal choice for automotive, industrial, and long-life battery applications where robustness and simplicity are critical.

Availability

TL7660ID is available at Aetrix Electronics and suitable for portable medical sensors, industrial data acquisition systems, automotive cabin control modules, and test & measurement equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TL7660ID 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

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, longevity, and automotive-grade qualification.

The TL7660 family was designed specifically for compact, diode-free DC/DC voltage inversion in space-constrained and thermally demanding applications - targeting portable instrumentation, industrial sensing, and automotive subsystems.

FAQ

What is the maximum continuous output current specification for TL7660ID at 125°C ambient?

The TL7660ID delivers up to 20 mA output current at V_CC = 5 V and T_A = 25°C. At full –40°C to +125°C operating range, the device maintains this rating with no derating, as confirmed by TI's electrical characteristics table under "–40°C to 125°C" test condition for ROUT and IO specifications. Thermal performance is ensured by SOIC-8's θ_JA = 97°C/W and internal thermal protection logic.

Can TL7660ID be used to generate a positive doubled voltage, and what external components are required?

Yes, TL7660ID supports positive voltage doubling per Figure 9 in the datasheet. It requires two external diodes (e.g., 1N4148) and two capacitors: C1 connected between CAP+ and CAP−, and C2 referenced to V_CC. The output V_OUT = 2V_CC – 2V_F, where V_F is the forward voltage of each diode. No changes to TL7660ID pin connections are needed beyond standard inverting mode wiring.

How does the LV pin affect TL7660ID operation below 3.5 V input, and what happens if it is left floating?

When V_CC < 3.5 V, the LV pin must be tied to GND to bypass the internal series regulator and minimize dropout. If left floating at low V_CC, the regulator remains active, causing excessive voltage drop and potential failure to regulate - verified by TI's "V_CC,LOW" parameter (1.5 V min only when LV = GND). Above 3.5 V, LV must float to enable latchup protection.

Is TL7660ID pin-compatible with the legacy ICL7660, and are there any layout considerations for replacement?

TL7660ID is functionally and pinout-compatible with ICL7660 in SOIC-8 (D) package, sharing identical pin assignments and footprint. However, TL7660ID adds LV pin functionality and improved latchup immunity. No PCB changes are required, but designers should verify C1/C2 values (10 µF recommended) and ensure GND routing meets low-impedance requirements per TI layout guidelines.

What is the minimum external capacitor value required on the OSC pin to reduce oscillator frequency to 1 kHz?

A 100 pF capacitor from OSC (pin 6) to V_CC reduces the TL7660ID oscillator frequency from 10 kHz to approximately 1 kHz, as shown in the "Oscillator Frequency vs Oscillator Capacitance" graph (Figure 1). This scaling is linear per TI's application note: f_OSC ∝ 1/C_OSC. Larger values further decrease frequency but require proportional increase in C1/C2 to maintain efficiency.