ADCMP600BRJZ-REEL7 Fast Comparator Selection Guide: How to Choose the Right Single-Supply Comparator

Bottom Line: When choosing a fast single-supply comparator for your next design, the three parameters that matter most are propagation delay (target <5 ns for high-speed applications), supply voltage range (2.5 V–5.5 V covers most modern 3.3 V and 5 V systems), and output type (push-pull vs. open-drain). The Analog Devices ADCMP600 series delivers sub-5 ns propagation delay with rail-to-rail inputs and outputs on a 2.5 V–5.5 V single supply, making it an excellent default choice for edge-detection, zero-crossing, and over-voltage protection circuits. Always verify that the comparator's input common-mode range covers your signal swing and that the output logic level is compatible with the downstream MCU or FPGA before committing to a package.

Introduction: Why Comparator Selection Matters

Voltage comparators are among the most deceptively simple building blocks in analog design, yet choosing the wrong device can cause subtle system failures that are difficult to diagnose. A comparator that is too slow will miss narrow pulses in motor-commutation feedback or phase-locked loop circuits. One with an insufficient input common-mode range will produce spurious outputs when the signal passes near the supply rail. An output type mismatch—connecting an open-drain comparator to a logic input without a pull-up resistor—can leave a bus floating indefinitely.

The ADCMP600 family from Analog Devices is among the most widely deployed fast single-supply comparators on the market. The ADCMP600BRJZ-REEL7 combines a 4.5 ns typical propagation delay with a 2.5 V to 5.5 V operating range, rail-to-rail inputs and outputs, and a 5-pin SOT-23 package that works equally well in hand-assembled prototypes and high-volume surface-mount production. This guide explains all the parameters you need to evaluate, provides a comparison table of leading candidates available through FindMyChip's distributor network, and gives you a decision flowchart to narrow your choice in minutes.

Key Selection Parameters

1. Propagation Delay

Propagation delay (t_PD) is the time elapsed from when the differential input voltage crosses zero to when the output reaches 50% of its final swing. It is specified at a defined overdrive level—typically 5 mV to 100 mV above the threshold—so always compare parts at the same overdrive when benchmarking. Comparators fall into three practical speed tiers: standard (>100 ns, e.g., LM393 at 1.3 µs), mid-speed (10–100 ns), and high-speed (<10 ns). The ADCMP600 family targets the high-speed tier with a t_PD of 4.5 ns typical at 5 V supply and 100 mV overdrive, enabling signal detection up to approximately 50 MHz. If your system uses signals below 1 MHz and quiescent current is a constraint, a 30 ns device like the ADCMP354YKSZ-REEL7 conserves power without impacting system performance. For signals above 100 MHz, you will need ECL or SiGe comparators outside the CMOS single-supply family.

2. Supply Voltage Range

Modern digital systems span an ever-wider voltage landscape: 1.8 V for low-power MCU I/O, 3.3 V for mainstream logic, 5 V for legacy and industrial interfaces, and up to 12 V for motor-driver gate signals. Choosing a comparator with a supply range that covers your system avoids a dedicated voltage rail and its associated LDO or regulator. The ADCMP600 family operates from 2.5 V to 5.5 V, making it compatible with 3.3 V and 5 V buses without an external level translator. For 1.7 V–5.5 V coverage, the ADCMP361YRJZ-REEL7 extends operation down to 1.7 V (VDDIO of modern BLE SoCs), accepting the tradeoff of a slower 70 ns propagation delay. For dual-channel operation at 1.7–5.5 V with open-drain outputs, the ADCMP343YRJZ-REEL7 packs two comparators into an 8-pin SOT-23 footprint.

3. Output Type: Push-Pull vs. Open-Drain

Push-pull (CMOS) outputs actively drive both logic HIGH and LOW, achieving fast rise and fall times without an external resistor. They are the preferred choice when the comparator output connects directly to a logic input on the same supply rail. Open-drain outputs only pull low; they require an external pull-up resistor to the desired logic supply. Open-drain offers two advantages: wired-AND or wired-OR connections (multiple comparators share one bus line), and voltage translation (a 3.3 V comparator can drive a 5 V pull-up rail). The ADCMP600BRJZ-REEL7 and ADCMP600BKSZ-REEL7 use push-pull outputs; the ADCMP343YRJZ-REEL7 and ADCMP361YRJZ-REEL7 use open-drain, which is also the JEDEC-standard output type for I²C-style shared-bus comparator networks.

4. Rail-to-Rail Input Common-Mode Range

A rail-to-rail input (RRIO) comparator accepts signals anywhere from the negative supply rail (GND in single-supply designs) to the positive supply rail. This is critical in three scenarios: (1) zero-crossing detectors where the sensed signal passes through 0 V, (2) over-voltage protection monitors where the signal approaches V_DD, and (3) battery management circuits where the cell voltage spans the full supply range. Non-RRIO comparators typically clip 0.5–2 V before each rail, creating dead zones that require level-shifting resistor dividers to compensate. The ADCMP600 family is fully RRIO according to the ADI datasheet, which rates the input common-mode range from −0.2 V to V_DD + 0.2 V. This 400 mV of beyond-the-rail headroom provides additional margin for systems where the input signal overshoots or undershoots due to parasitic inductance on PCB traces.

5. Hysteresis

Comparator hysteresis (also called Schmitt threshold) is a deliberately introduced offset between the rising and falling thresholds that prevents chattering when the input signal is slow-moving or noisy near the threshold. Without hysteresis, a signal with even millivolts of noise will toggle the output hundreds of times per second. Built-in hysteresis (typically 2–10 mV in high-speed CMOS comparators) is part of the device specification; it cannot be removed. The ADCMP600 has approximately 2 mV of built-in hysteresis, which is sufficient for most clean-signal applications. For noisier environments (motor halls, automotive), use a resistor-feedback network to add external hysteresis: a 100 kΩ pull-up from output to non-inverting input provides 50 mV of hysteresis on a 5 V rail with a 10 kΩ input resistor.

6. Package and Footprint

Comparators are available in a wide range of packages: SC-70 (4–5 pin, ~1.6 × 1.6 mm), SOT-23 (5–6 pin, ~3 × 1.75 mm), SOT-143, MSOP (8–10 pin), SOIC, and WLCSP. Reel size—7-inch (7,000 units) vs. 13-inch (10,000 units)—matters for production planning. The ADCMP600BRJZ-REEL7 uses a 5-pin SOT-23 on a 7-inch reel, a combination that suits medium-volume runs and is the most reflow-soldering-friendly format for contract manufacturing in Asia. The ADCMP600BKSZ-REEL7 uses SC-70 for tighter board density. For the smallest possible footprint, the ADCMP380-1ACBZ-RL7 offers a WLCSP-6 package, though it requires a high-density layout and is not hand-solderable.

7. Quiescent Current

Quiescent supply current (I_Q) is the current consumed by the comparator when its output is static. High-speed comparators trade low I_Q for bandwidth. The ADCMP600 draws approximately 1.3 mA typical at 5 V, which is negligible in most wall-powered designs but significant in coin-cell-powered nodes. If the application requires comparator operation only during event detection (not continuously), consider duty-cycling the supply using a GPIO-controlled LDO. For always-on battery applications with signals below 10 kHz, the nanopower comparators in the ADCMP36x family (I_Q as low as 1.2 µA) extend battery life by three orders of magnitude.

8. Number of Channels and Integration

Single-channel comparators like the ADCMP600 are optimal when exactly one threshold comparison is needed; they minimize quiescent current and simplify fault isolation. Dual-channel parts pack two independent comparators into a single footprint—the ADCMP343YRJZ-REEL7 fits two 70 ns open-drain comparators in an 8-pin SOT-23, ideal for window detectors that flag both under-voltage and over-voltage conditions. Quad comparators like the ADCMP393ARZ combine four open-drain comparators in a 14-pin SOIC, which is common in multi-phase motor controllers and battery management systems where four cell voltages must be monitored simultaneously.

Recommended Products Comparison Table

Product	Speed (t_PD)	Supply Range	Output Type	Package	Best For
ADCMP600BRJZ-REEL7	4.5 ns	2.5–5.5 V	Push-Pull	SOT-23-5	High-speed edge detection, 3.3 V/5 V systems
ADCMP600BKSZ-REEL7	4.5 ns	2.5–5.5 V	Push-Pull	SC-70-5	Compact high-density boards
ADCMP361YRJZ-REEL7	70 ns	1.7–5.5 V	Open-Drain	SOT-23-5	Low-voltage 1.8 V systems, wired-OR buses
ADCMP343YRJZ-REEL7	70 ns	1.7–5.5 V	Open-Drain	SOT-23-8	Window detectors, dual-threshold circuits
ADCMP393ARZ	150 ns	2.3–5.5 V	Open-Drain	SOIC-14	Multi-channel protection, BMS circuits
LMV7219M5/NOPB	7 ns	2.7–5 V	Push-Pull	SOT-23-5	TI-ecosystem 5 V push-pull applications

Selection Decision Flowchart

Work through the following logic tree to identify the best candidate for your design:

Step 1 — What propagation delay do you need?

• Less than 5 ns → Proceed to Step 2 with ADCMP600 family.
• 5–30 ns → Consider ADCMP354YKSZ-REEL7 (push-pull) at lower I_Q.
• 30–100 ns and very low power → Consider ADCMP361YRJZ-REEL7 or ADCMP343YRJZ-REEL7.
• Greater than 100 ns and ultra-low power → Use nanopower ADCMP36x or ADCMP38x variants.

Step 2 — What is your supply voltage?

• 2.5 V to 5.5 V → Full ADCMP600 family is eligible.
• 1.7 V to 2.5 V → ADCMP361YRJZ-REEL7 or ADCMP343YRJZ-REEL7 required.
• Below 1.7 V → Consult the ADCMP38x WLCSP family.

Step 3 — Push-pull or open-drain output?

• Push-pull (direct logic drive, fastest edge) → ADCMP600BRJZ-REEL7 (SOT-23) or ADCMP600BKSZ-REEL7 (SC-70).
• Open-drain (wired-OR bus, voltage level shift) → ADCMP361YRJZ-REEL7 or ADCMP343YRJZ-REEL7.

Step 4 — How many channels?

• 1 channel → ADCMP600BRJZ-REEL7.
• 2 channels → ADCMP343YRJZ-REEL7.
• 4 channels → ADCMP393ARZ.

Step 5 — What package do you need?

• Standard SOT-23, 7k reel → ADCMP600BRJZ-REEL7.
• Smaller SC-70, tighter board → ADCMP600BKSZ-REEL7.
• Ultra-small WLCSP → ADCMP380-1ACBZ-RL7.

Application Examples

Over-Voltage Protection Monitor. A battery charger must latch off when V_BAT exceeds 4.25 V. Connect a resistor divider (820 kΩ / 390 kΩ) from V_BAT to the non-inverting input of an ADCMP600BRJZ-REEL7, with a 4.1 V reference on the inverting input. When V_BAT rises above 4.25 V, the output goes HIGH and drives a P-channel MOSFET gate to cut off charging current. The 4.5 ns propagation delay ensures the circuit reacts within a single switching cycle of a typical 500 kHz charger IC.

Zero-Crossing Detector for Motor Commutation. BLDC motor controllers require zero-crossing detection on back-EMF signals that swing from GND to the motor supply. A rail-to-rail input comparator like the ADCMP600 handles the full 0 V–5 V swing without a biasing network. Configure hysteresis by connecting a 2 MΩ resistor from the output to the non-inverting input; at 5 V supply this adds approximately 5 mV of hysteresis to reject noise near the zero-crossing transition point.

Window Detector Using Dual Comparator. For detecting signals within a ±5% tolerance band, use the ADCMP343YRJZ-REEL7 in a window-detector configuration: connect both open-drain outputs to a shared pull-up resistor. Comparator A trips when the signal exceeds V_HIGH; Comparator B trips when the signal falls below V_LOW. The wired-AND output is HIGH only when the signal is within the window.

FAQ

What is the propagation delay of the ADCMP600BRJZ-REEL7? The ADCMP600BRJZ-REEL7 specifies a typical propagation delay of 4.5 ns at a 5 V supply, measured at 100 mV overdrive from input crossing to 50% output level. This makes it one of the fastest rail-to-rail single-supply CMOS comparators at its price point, suitable for edge-detection applications at signal frequencies up to approximately 50 MHz, including zero-crossing detection, clock recovery, and fast over-voltage protection circuits.

Can the ADCMP600 series operate from a 3.3 V single supply? Yes. The ADCMP600 family is rated from 2.5 V to 5.5 V single supply, so 3.3 V operation is fully within the specification. Both the rail-to-rail input and push-pull output function correctly at 3.3 V, and the CMOS output logic levels (V_OH ≥ V_DD − 0.4 V, V_OL ≤ 0.4 V) are compatible with 3.3 V GPIO inputs on STM32, nRF52, ESP32, and most other modern MCUs.

What is the difference between ADCMP600BRJZ-REEL7 and ADCMP600BKSZ-REEL7? Both parts are the ADCMP600 die with identical electrical specifications: 4.5 ns propagation delay, 2.5–5.5 V supply, push-pull output, and rail-to-rail I/O. The only difference is the package. BRJZ-REEL7 is a 5-pin SOT-23 (approximately 3.0 × 1.75 mm footprint), while BKSZ-REEL7 is a 5-pin SC-70 (approximately 2.0 × 1.25 mm footprint), about 40% smaller. Both ship on 7-inch (7,000-unit) reels. Choose SOT-23 for easier hand soldering and rework; choose SC-70 when board real estate is constrained.

When should I choose an open-drain comparator instead of a push-pull comparator? Choose open-drain when: (1) two or more comparator outputs must share one signal line in a wired-AND or wired-OR topology; (2) the comparator supply is lower than the logic supply of the downstream device, requiring a pull-up to a higher voltage (e.g., 3.3 V comparator driving a 5 V input via a 5 V pull-up); or (3) the output drives a microcontroller interrupt pin that has an adequate internal pull-up. For all other single-ended point-to-point connections, push-pull is faster and requires fewer external components.

How does ADCMP600 compare to the Texas Instruments LMV7219? Both are 5-pin SOT-23 push-pull comparators for single-supply operation. The ADCMP600 specifies 4.5 ns typical propagation delay versus the LMV7219's 7 ns; the ADCMP600 also extends operation to 2.5 V versus the LMV7219's 2.7 V minimum. The LMV7219 is a well-established TI part with broad global availability and competitive pricing in small quantities, making it attractive for teams already in the TI supply chain. For the lowest latency in a 5 V system, the ADCMP600 has a measurable advantage. Compare live stock and pricing for both parts via FindMyChip.

Conclusion and Next Steps

Choosing the right fast comparator requires matching four parameters—propagation delay, supply voltage, output type, and channel count—to your actual system constraints. For sub-5 ns performance on a 2.5 V–5.5 V single supply with push-pull output, the ADCMP600BRJZ-REEL7 is a proven, cost-effective choice available from multiple verified distributors. For lower supply voltages or open-drain bus applications, the ADCMP361 and ADCMP343 families extend coverage without leaving the Analog Devices ADCMP ecosystem. For Texas Instruments ecosystem designs, the LMV7219M5/NOPB provides a 7 ns push-pull alternative with broad distributor availability.

FindMyChip connects hardware teams with 200+ verified distributors, all subject to 5-point authentication, ensuring you receive genuine Analog Devices and TI parts with full traceability. Search for ADCMP600 inventory now or submit a quote request for your BOM to receive competitive pricing from Shenzhen-based authorized distributors within 24 hours.